O
OBO - OCD

OBOE - nouns
• HAUTBOY an oboe ...1575
• HAWBOY a hautboy; an oboe ...1889 Eng. dial.
• HOBOY an oboe ...1575
• WAITS † wind instruments, either hautboys (oboes), flutes, or shawms (forerunner of the oboe) ...1530
oboe - person 
• HAUTBOY an oboe player ...1633
• HAUTBOYIST a player on the oboe ...1864
• HOBOY an oboe player ...1633
 
OBSCENE - adjectives
• BARNYARD smutty, obscene ...20C US sl.
• BAWDISH †* obscene, filthy ...1572
• BAWDY pert. to or fitting a bawd; lewd, obscene, unchaste; chiefly applied to language ...1513
• BESTIAL like a beast in obeying and gratifying the animal instincts and sensual desires; debased, depraved, lustful, obscene ...1447
• BLACKGUARD characterized by abusive or obscene language ...1806 Amer. dial.
• BLUE coarse, obscene, esp. of a joke, story, film, etc.; having sexual content, pornographic ...1818 colloq.
• FEELTHY obscene ...M20 sl.
• FULL-FLAVOURED really rotten; obscene ...sl.
• HIGH-SEASONED of literature: somewhat lewd, obscene ...B1900
• ITHYPHALLIAN † grossly indecent, obscene ...1693
• ITHYPHALLIC grossly indecent, obscene ...1856
• NAUGHTY pornographic; erotic; obscene; loose ...1882 euphemism
• OBSCENOUS † obscene ...1604
• OFF-COLOUR tending to be indecent, obscene, lewd, or lascivious, but hinting at or suggesting the obscene ...1875 sl.
• OLD-FASHIONED obscene ...1930s sl.
• MEATY obscene; with significant sexual content ...20C
• PORNY lewd; smutty or obscene; pornographic ...1961 Brit. & US sl.
• RAUNCHY racy, obscene, or off-colour ...1967 US sl.
• REASTY bad-tempered; also, gross, obscene ...1825 Eng. dial.
• ROTTEN of language: morally offensive; obscene ...1589
• SALTY unpleasant, uncouth, crude; of language: obscene ...1920s US teen sl.
• SCABROUS indecent or scandalous; risqué; obscene 
• SMUTTY obscene, bawdy ...17C
• SPURCIDICAL † speaking dishonestly, obscenely, or smuttily; bawdy in speech ...1656
• SPURCITIOUS †* filthy, foul, obscene ...1628
• ULTRAMARINE obscene, smutty ...L19 sl.      
• UNPARLIAMENTARY obscene ...M19 sl.
• WORD-WANTON obscene in speech ...B1900
obscene - nouns  (includes OBSCENITY)
• BALDERDASH filthy or obscene talk or writing; impudent language; abuse ...1715 Eng. dial.
• BAWDINESS lewdness, obscenity ...1731
• BAWDRY lewdness in speech or writing; lewd, obscene, or filthy talk, etc. ...1589 arch.
• BAWDY lewd, obscene language, lewdness, obscenity ...1698
• BELCH worthless or obscene conversation ...Bk1898 Eng. dial.
• BESTIALITY filthy language, obscenity ...1879
• BROAD STATEMENT speech that includes obscenity and cussing ...1969 Amer. dial.
• BROAD TALKING speech that includes obscenity and cussing ...1969 Amer. dial.
• DAMSON-PIE abuse; a slanging match; obscene language ...c1865 colloq.
• DIRT filth, obscenity, scurrilous information or gossip ...1926 sl.
• FRENCH POSTCARDS obscene pictures ...M19 colloq.
• FRENCH PRINTS obscene pictures ...M19 colloq.
• GUTTER LANGUAGE profanity and obscenity; scabrous speech ...1890 Amer. sl.
• HARLOTRY † buffoonery, jesting; ribaldry, scurrility, scurrilous talk; obscene talk or behaviour ...c1325
• MILLER an obscene story ...Bk1905 Eng. dial.
• NAST obscenity ...1790 Eng. dial.
• ONE-FINGER SALUTE an obscene gesture; the 'finger' ...M20 US sl.
• RAUNCH obscenity, pornography ...1960s sl., orig. US
• SHIT DETAIL any unpleasant or dirty talk ...1940s sl., orig. military
• SMUT 1. an obscene story; pornography in general ...17C
2. obscene language ...17C
• SMUTS obscene pictures ...E20 US criminals' sl.
• UNPARLIAMENTARY LANGUAGE language unfit for polite discussion; violent or obscene language ...Bk1958 sl.
obscene - person
• BARRACKER one using low language to aid his party ...Bk1895 Aust. criminals' sl.
• DIRTY-MOUTH a person who talks dirty, uses obscene language ...Bk2006 US sl.
• GARBAGE MOUTH a person who regularly uses obscene language; a foul-mouthed person ...1970 US sl.
• HAWCH-A-MOUTH a foul-mouthed, blustering person; one who talks incessantly in a coarse, vulgar manner using obscene and offensive language ...1746 Eng. dial.
• HAWCH-MOUTH a foul-mouthed, blustering person; one who talks incessantly in a coarse, vulgar manner using obscene and offensive language ...1746 Eng. dial.
• LATRINE LIPS someone (usually a citizens band radio operator) who habitually uses obscene language ...M20 US sl.
• LEWDSBY † a lewd or obscene person ...1594
• LEWDSTER * a lewd or obscene person ...1598
• POTTY MOUTH someone who uses obscene or profane language in most social settings; a foul-mouthed person ...1969 colloq., orig. US
• SALTY DOG one who uses an excess of obscene language ...1983 US Black sl.
• SMUTHOUND 1. a man who revels in obscenity and pornography ...M20 US sl.
2. a censor; someone who is hunting for smut ...M20 US sl.
obscene - verbs  (includes OBSCENITY)
• BADMOUTH to utter obscenities ...1972 US sl.
• BLACKGUARD to talk obscenely; to curse or swear at ...1902 Amer. dial.
• BLAGGARD to talk obscenely; to curse or swear at ...1902 Amer. dial.
• KEEP THE PARTY CLEAN to avoid obscenity or 'dirty' stories ...1930s sl. ​
• MAKE THE AIR BLUE to swear profusely; to use obscene language ...1887
• SMUT to make something obscene ...17C
• TALK BAWDY to talk lewdly or obscenely ...1656
• TURN THE AIR BLUE to swear profusely; to use obscene language ...1867
• WORK BLUE to use obscene language; to peddle smut ...1990s Amer. sl.
obscene - phrases
• DO YOU EAT WITH THAT MOUTH? said to someone who talks dirty or obscenely all the time ...Bk2006 US sl.
• READ MY LIPS used to convey that one is thinking something insulting or obscene but choosing not to speak it ...1980s sl.
 
OBSCURATION - nouns
• ADUMBRATION overshadowing; shade, obscuration ...1653
• OBFUSCATION a darkening, obscuration ...1608
• OBFUSCITY * a darkening, obscuration ...1832
• OBNUBILATION the act of darkening or fact of being darkened as with a cloud; obscuration ...1610
• OFFUSCATION * a darkening, obscuration ...1502
 
OBSCURE - adjectives
• BECLOUDED made obscure or gloomy ...1581
• CALIGINOUS misty, dim, murky; obscure, dark ...1548 now arch.
• CREPUSCULOUS of the nature of twilight; in a state between light and darkness; dim, glimmering, dusky, indistinct, obscure ...1646
• DARK hard to understand; obscure in meaning ...c1320
• DARKLING lying in darkness; showing itself darkly; darksome, obscure ...1739
• DARKSOME dark, obscure; ill-lighted ...1781 Sc. & Eng. dial.
• DERN secret, obscure ...1814 Sc. & Eng. dial.
• FOGGY obscure or confused
• IMPERSPICUOUS * not perspicuous or clear; obscure ...1721
• INVOLUTE hidden, obscure ...M17
• LATESCENT becoming hidden or obscure ...1836
• MIRK dark, gloomy, obscure, dusky ...1671 Sc. & Eng. dial. 
• OBLITE †* dim, as if partly blotted out; indistinct, obscure ...1650
• OBSCURATIVE †* tending or serving to obscure or render dark ...1664
• OBSCUROUS †* dark, gloomy, obscure ...1491
• OBUMBILATE †* obscure ...c1560
• OPACOUS † lying in shadow; not illuminated, darkened, obscure ...1621-3
• OPAQUE † lying in shadow; not illuminated, darkened, obscure ...c1420
• ORACULOUS † abstruse, profound, obscure ...1625 rare or obs.
• TENEBRICOSE * full of darkness; very dark, obscure; gloomy ...1730-6
• TENEBROUS obscure, gloomy ...1599
• THESTER † dark, obscure ...a900
• UMBRAGEOUS † obscure; dubious ...1635
• UMBRAGIOUS † obscure; dubious ...1635
• UNKENSPAK inconspicuous, obscure ...Bk1905 Eng. dial.
obscure - nouns
• EFFUSCATION †* the act of making obscure; a beclouding ...1624
• NEBULA * a misty or obscure affair ...a1734
obscure - person 
• FARTKNOCKER any obscure person; a person whose name you don't know or remember ...1984 Amer. dial.
obscure - verbs 
• ADUMBER †* to overshadow, to obscure ...1535
• ADUMBRATE to overshadow; to shade, to obscure ...1670
• ADUMBRE †* to overshadow, to obscure ...1535
• BECLOUD to make obscure; to darken, to hide ...1619
• BEFOG to obscure, to confuse ...1603
• DARK 1. to obscure, to cloud, to dim, to sully ...c1374 arch.
2. † ​to cloud, to dim, to obscure, to hide something luminous ...c1380
• DARKLE to render dark or obscure ...1884
• OBFUSCATE * to darken, to obscure (physically); to deprive of light or brightness; to make dark or dusky ...1650
• OBFUSK † to darken, to obscure (physically); to deprive of light or brightness; to make dark or dusky ...1490
• OBNEBULATE * to obscure as with a mist; to befog, to cloud ...c1540
• OBNUBILATE to darken, dim, cover, or hide with or as with a cloud; to overcloud; to obscure ...1583
• OBSCURIFY †* to make obscure; to hide ...1622
• OBUMBER † to overshadow; to shade, to obscure ...c1420
• OBUMBILATE †* to obscure ...a1711
• OBUMBRATE * to overshadow; to shade, to darken; to obscure ...1526
• OFFUSCATE * to darken, to obscure (physically); to deprive of light or brightness; to make dark or dusky ...1656
• OFFUSQUE †* to darken, to obscure ...a1751
• SEND TO THE PACK to relegate to obscurity ...1916 Aust. sl. ​
 
OBSCURED - adjectives
• ADNUBILATED * darkened by clouds; clouded; obscured ...1730 
• DELITESCENT lying hid, concealed, or obscured ...1684
• OBFUSCATE † darkened, obscured ...1531 rare or obs.
• OBNUBILATE † covered or darkened as with a cloud; overclouded; obscured ...1560
• OBSCURATE † obscured; darkened ...1471
• OFFUSCATE * darkened, obscured ...1603
 
OBSCURELY - adverbs
• UNDERGROUND in secrecy or concealment; in a hidden or obscure manner ...1632
 
OBSCURITY - nouns
• ABSTRUSITY obscurity; anything abstruse; an obscure or recondite matter or point ...1646 arch.
• DARKSOMENESS darkness, obscurity ...1571
• INPERSPICUITY the reverse of perspicuity or clearness; obscurity ...1659
 
OBSEQUIOUS - adjectives
• ASS-KISSING obsequious, sycophantic ...1952 Amer. sl.
• ASS-LICKING obsequious, sycophantic; hence, despicable, goddamned ...1939 Amer. sl.
• BUTTOCK-LICKING obsequious, sycophantic; hence, despicable, goddamned ...1921 Amer. sl.
• COMPLACENTIOUS † complaisant, obsequious, soothing, and thereby, pleasing ...1656
• MEACHING skulking, cringing; self-deprecating, obsequious; contemptible, useless, good-for-nothing ...1792 Amer. dial.  
• MEECHING skulking, sneaking, creeping softly; cringing; self-deprecating, obsequious; contemptible, useless, good-for-nothing ...1792 Eng. & Amer. dial.
• MICHING skulking, cringing; self-deprecating, obsequious; contemptible, useless, good-for-nothing ...1792 Amer. dial.
• UP EACH OTHER behaving obsequiously, or in a sycophantic manner towards each other ...1940s Aust. sl.
obsequious - nouns  (includes obsequiousness) 
• ARSE-LICKING obsequious behaviour; toadying ...1912 sl.
• ASS-KISSING obsequious behaviour; toadying ...1942 sl., chiefly US
• BUM-SUCKING obsequious behaviour; toadying ...1949 Brit. sl.
• KOWTOW an act of obsequious respect ...1834
• OBSEQUENCE * compliance, complaisance, obsequiousness ...1603
• OBSEQUIOSITY obsequiousness ...1885
• OBSEQUITY * obsequiousness ...1892
• OBSEQUY * ready compliance with the will or pleasure of another, esp. of a superior; deferential service; obsequiousness ...1432-50
• PULLING WOOL acting in an obsequious manner ...1869 Amer. dial.
• UNCLE TOMMING (derogatory) behaving obsequiously toward White people ...1944 Amer. dial.
obsequious - person
• APPLE-POLISHER an obsequious person; a toady; a sycophant; a flatterer ...Bk1892 colloq., orig. & chiefly US
• ARSE-LICKER an obsequious person; a toady; a sycophant ...1938 sl.
• ASS-LICKER an obsequious person; a flatterer; a sycophant, a toady ...1939  US sl.
• ASS-KISSER an obsequious person; a toady, a sycophant ...1766 sl., chiefly US
• ASS WIPE a worthless, contemptible person, esp. if also obsequious; one who curries favour; a toady ...1952 Amer. sl.
• BACK PATTER an obsequious person; a sycophant; a toady  ...Bk1942 Amer. sl.
• BACK-SCRATCHER one who praises you for your praise of him or her; an obsequious person; a flatterer, a sycophant, a toady ...1897
• BACK SLAPPER an obsequious person; a sycophant; a flatterer; a toady ...Bk1942 Amer. sl.
• BOOTKISSER a flattering, fawning, obsequious person; a toady ...1966 Amer. dial.
• BOOTLICK a flattering, fawning, obsequious person; a toady, a sycophant; one who tries to curry favour ...1849 Amer. dial.
• BROWN-NOSE an obsequious person; a toady; a sycophant ...1938 sl., orig. US military usage
• BROWN-NOSER an obsequious person; a toady; a sycophant ...1950 sl., orig. US military usage
• BUM-SUCKER an obsequious person; a toady; a sycophant ...1877 Brit. sl.
• COCKSUCKER (derogatory) an obsequious and flattering male; a male sycophant ...Bk2006 US sl.
• CRAWLER an obsequious person; a toady; a sycophant ...1892 sl., orig. Aust.
• ECHO one who assents obsequiously to the opinions of another; a person who reflects or imitates the language, sentiments, or conduct of others ...a1631
• GREASER an obsequious person; a toady; a sycophant ...1900 sl.
• KOWTOWER an obsequious person; a toady ...1961
• LACKEY, LACQUEY one who is servilely obsequious; a toady; a yes-man ...c1692
• LIMBERHAM † one who has 'limber hams', a supple-jointed person; fig. a servile flatterer; an obsequious person ...1689
• OBSERVICER †* one who shows respect, deference or dutiful attention; an obsequious follower ...1625
• SUCK an obsequious person; a toady; a sycophant; a schoolchild who curries favour with teachers ...1900 sl.
• TANTONY a servile flatterer; a parasite; one who obsequiously follows another ...1659
• TANTONY PIG a servile flatterer; a parasite; one who obsequiously follows another ...1738
• WAGTAIL † a familiar or contemptuous epithet or form of address applied to a man or young woman; an obsequious person ...1605
• YES-GIRL an obsequiously subordinate woman ...1930
• YES-MAN a man who agrees from self-interest or fear with everything put to him by a superior; an obsequious subordinate; one who always says yes to their superiors in the belief that this is what they like to hear; a sycophant; a toady; a flatterer ...1912 colloq., orig. US
• YES-WIFE an obsequiously subordinate woman ...1912
• YES-WOMAN an obsequiously subordinate woman ...1933
obsequious - verbs
• AK to curry favour by obsequious behaviour (Ass-Kiss) ...1939 US sl.
• ARSE-LICK to behave obsequiously towards; to toady ...1968 sl.
• ASSHOLE to grovel, to submit or behave obsequiously ...1940 Amer. sl.
• ASS-KISS to curry favour with in a self-degrading manner; to toady; to behave obsequiously to ...1961 Amer. sl.
• ASS-LICK to curry-favour; to be obsequious ...1937 sl., orig. US
• BUM-SUCK to behave obsequiously towards; to toady ...1930 Brit. sl.
• CRAWL to behave obsequiously towards; to toady ...1881 sl., orig. Aust.
• JEFF to behave obsequiously, esp. towards Whites; to humiliate oneself ...1960s US Black sl.
• KISS SOMEONE'S ARSE to behave obsequiously or sycophantically towards ...1749 sl.
• KISS SOMEONE'S ASS to be obsequious or sycophantic towards someone; to curry favour with someone ...1749 sl.
• KOWTOW to act in an obsequious or obedient manner ...1826
• LICK SOMEONE'S ARSE to behave obsequiously towards ...1864 sl.
• LICK SOMEONE'S ASS to curry favour with someone, esp. in a blatant or degrading manner; to behave obsequiously towards ...1864 Amer. sl.
• PISS IN SOMEONE'S POCKET to behave obsequiously towards ...1967 Aust. sl.
• SUCK AROUND to behave obsequiously ...1931 sl., orig. & chiefly US
• SUCK-HOLE to behave obsequiously towards ...1961 sl., orig. & chiefly Can.
• SUCK UP (TO) to behave obsequiously towards ...1860  sl.
 
OBSERVABLE - adjectives
• PALPABLE readily perceived by some one of the other senses, as the sight, hearing, etc.; perceptible; plainly observable, noticeable ...c1430
 
OBSERVANCE - adverbs
• OBSERVANTIALLY †* with careful observance ... rare
 
OBSERVANT - adjectives
• ABER sharp-sighted; keenly observant; watchful ...1908 Sc.
• ADVISIVE †* observant, prudent ...1436
• EYEFUL † observant, vigilant; later, careful ...1594 obs. exc. Eng. dial.
• MARKING † observing, observant ...1577-87
• OBSERVATIVE * pert. to observation; observant, attentive, heedful ...1611
• OCCULATE † possessed of eyes or sight; sharp-sighted; observant ...1615
• OCULATE † possessed of eyes or sight; observant, sharp-sighted ...1549
• PERCEIVANT †* perceiving, observant, observing, understanding ...c1400
observant - person 
• BIG EYE an especially observant, cautious person ...Bk1992 sl. 
• OCULIST †* one who has good eyes, or uses them well; a sharp-sighted or observant person ...1660
observant - verbs 
• BE ALL EYES to watch attentively; to be keenly observant; to be alert and vigilant ...a1616
• KEEP NIT to keep watch, be observant ...1903 Aust. sl.
• KEEP YOUR EYES PEELED to be extra-observant ...1833 US sl.
• KEEP YOUR EYES SKINNED to be extra-observant ...1810s US sl.
• KEEP YOW to keep watch, be observant ...1942 Aust. sl.
 
OBSERVATION - adjectives
• OBSERVATICAL †* pert. to (scientific) observation; observational ...1703
• OBSERVATIVE * pert. to observation; observant, attentive, heedful ...1611
• OBSERVATIVE †* worthy of observation; observable ...1608
observation - nouns 
• ADVERTATION †* the act of turning the attention; observation, notice ...c1480
• ADVERTENCE the act of turning the attention to; observation, notice, heed, attention, consideration ...c1370
• ADVERTISEMENT † the turning of the mind to anything; attention, observation, heed ...1523
• ADVISEMENT † the process of looking at or viewing; observation, notice, attention, consideration ...1330
• CASES observation; scrutiny ...Bk1914 criminals' sl. 
• GAZEMENT * stare, look, observation ...1596
• OBBO observation work ...c1919 policemen's sl.
• OBBS surveillance; observation; a lookout ...1933 UK sl.
• OBO surveillance; observation; a lookout ...1933 UK sl.
• OBS surveillance; observation; a lookout ...1933 UK sl.
• OBSERVAL † the act of observing; observation; observance ...a1734
• OBSERVE an observation, scientific or otherwise, a remark, a comment ...1700 Sc.
• TENT a look; observation, notice, attention ...1824 Sc. & Eng. dial.  
• WAITING † watching, observation ...1377
observation - person
• OBSERVATOR 1. † one who marks, notes, or makes observations; formerly a frequent name for a newspaper or pamphlet, and often applied to the editor or writer ...1642
2. † ​one who makes a verbal observation ...1660
• OBSERVIST one who makes observation his business ...1827 nonce word
observation - phrases
• QUICK THINKING, BATMAN used for a humorous, if sarcastic, response to another's observation or conclusion ...1968 US sl.

OBSERVE - verbs
• ADNOTE †* to note, to remark, to observe ...1558
• ADVERT † to turn the attention to; to take note of; to observe, to note, to heed; to consider, to think of a thing ...1430
• ADVERTISE † to notice, to observe a thing ...c1430
• ADVISE † to look at, to view, to observe, to consider, to watch; also, to watch for ...1297
• CASE to watch; to observe; to scrutinize ...Bk1914 criminals' sl. 
• CLOCK to look at, watch, observe, notice ...M20 sl.
• COGNIZE to take note of, to notice, to observe; to know or perceive, to recognize ...1821
• EAGLE-EYE to observe and evaluate closely; to scrutinize ...1964 Amer. sl.
• GET ON TO to look at; to notice; to observe appreciatively or critically ...1882 US sl.
• KEEP † to take in with the eyes, ears, or mind; to take note of, to behold, to observe ...c1000
• MARK to observe, to watch, to see, to spy ...1377 now poetic
• MIND to observe, to notice; to pay attention or heed to ...1838 Sc. & Eng. dial.
• OBSERVATE †* to observe ...1652
• OFSEE † to see, to perceive by sight; to catch sight of, to observe ...c1000
• PENNY to observe, to scrutinize ...1990s W. Indies sl.
• QUOTE † to make mental note of; to notice, to observe, to mark, to scrutinize ...1588
• RADDLE to mark, observe, watch ...Bk19C Eng. dial.
• SIGHT to observe, to see ...1930s UK criminals' & Black sl.
• SKANK to observe members of the opposite sex ...1980s US campus sl.
• SMOKE OVER to look over, to observe critically ...1928 Amer. dial.
• TAKE TENT OF to pay attention to; to notice, to observe ...1824 Sc. & Eng. dial.
• TENT to see, to observe, to notice ...1784 Sc.
• VADA to see; to look; to observe ...1859 UK sl.
• VARDA to see; to look; to observe ...1859 UK sl.
• VARDI to see; to look; to observe ...1859 UK sl.
• VARDO to see; to look; to observe ...1859 UK sl.
• VARDY to see; to look; to observe ...1859 UK sl.
• VAREEZ to notice, to observe ...a1838 Sc.
• WAIT 1. † to watch, to keep one's eye upon, to observe constantly; to look out for, to watch for ...a1300
2. † ​to observe carefully ...1399
 
OBSERVED - nouns
• NOTANDUM an entry of something to be specially noted; a thing to be noticed or observed; a memorandum ...1685
• OBSERVANDUM * something to be observed or noted ...1704
 
OBSERVER - person
• BIRD DOG a watcher, an observer ...1952 US sl.
• EAGLE-EYE an observer or lookout ...1945 Amer. jocular
• EYER * a person who looks or sees someone or something; an observer; chiefly literary and poetic usage ...1611
• FLY ON THE WALL an unperceived observer; one who is able to overhear discussions, etc., without being observed or involved ...1949
• KEEKER one who watches or pries; a surreptitious observer of others; a peeping Tom ...1892 Sc.
• MARKER † one who notes or observes ...c1550
• OBSERVATRIX †* a female observer ...1653
• SHOWER † a person who looks out or observes; an observer; a scout; a watchman; also, a person who makes an inspection or examination of something ...a1225
• WAITER † one who watches or observes closely; one who is on the lookout ...1382
 
OBSERVING - adjectives
• MARKING † observing, observant ...1577-87
• NARROW-EYED †* observing closely ...1599
• PERCEIVANT †* perceiving, observant, observing, understanding ...c1400
observing - nouns 
• OBSERVAL † the act of observing; observation; observance ...a1734
 
OBSESSED, OBSESSIVE - adjectives
• DEAD SET ON fascinated by, obsessed with, in love with, determined ...L19 sl.
• EAT UP keen on, obsessed with ...1990s sl.
• GOOFY obsessed; keen on ...1910s US sl.
• HUNG fascinated or obsessed with ...1950 US sl.
• HUNG UP obsessed, infatuated ...1950 US sl.
• HUNG UP ON obsessed ...1957 sl.
• IN BITS OVER obsessed with ...L19 sl.
• INSANE idiotic, utterly senseless, irrational, obsessive ...M19
• LOCO crazy, insane, mentally deranged, out of one's mind; obsessed ...1887 Amer. dial.
• PASH passionate, obsessive ...1920s sl.
• PASHED UP sexually obsessed ...1930s US sl.
• QUEER FOR obsessed with, sexually or otherwise ...1940s sl.
• STUCK obsessed with, devoted to ...M19 orig. US
• STUCK AFTER obsessed with, devoted to ...M19 orig. US
• STUCK ON obsessed with, devoted to ...M19 orig. US
• TABANKCA passionate, obsessed ...20C W. Indies sl.
• WHALES ON obsessed with, devoted to ...L19 US sl.
obsessed, obsessive - person
• ANORAK someone obsessively involved with something, as a hobby, that is generally regarded as boring or unfashionable ...1991 Brit. sl.
• BEETLE a crazy, eccentric, or foolish person; a madman, an obsessive fan ...1605 sl.
• CRANK a mentally unstable person; an unreliable, unpredictable person; a person who is obsessed by a single topic or hobby ...1833 US sl.
• LOCO (derogatory) one who is out of his mind or obsessed; a crazy or insane person ...1852 Amer. dial.
• LOCO BLOSSOM (derogatory) one who is out of his mind or obsessed; a crazy or insane person ...1941 Amer. dial.
• MONSTER an obsessive, an addict ...1998 sl.
• TRAINSPOTTER anyone with a pedantic interest in and an obsessive knowledge of a specific topic ...1995 UK sl. 
obsessed, obsessive - verbs 
• DO ONE'S JOB OVER to become obsessed with ...1970s Aust. sl.
• GO APE-SHIT to be obsessed with a person or thing ...M20 US sl.
• HAVE BEES IN THE HEAD to be whimsical or obsessed with something ...a1553
• PUT ONE'S EYE ON to become obsessed with at first sight and thus to desire to possess immediately ...20C W. Indies
 
OBSESSION - nouns
• BEE IN ONE'S BONNET an obsession with something ...1845
• BUG an obsessive enthusiasm or craze; an obsession or urge ...1902 sl., orig. US
• BUG UP ONE'S ASS an obsessive desire; a stimulus, a goad ...1954 Amer. dial.
• GREAT WHITE WHALE an objective earnestly and relentlessly pursued; an obsession ...1992
• RAT an obsession, an eccentricity ...1920s sl.
• WHITE WHALE an objective earnestly and relentlessly pursued; an obsession ...1931
obsession - person 
• TRAINSPOTTER anyone with a pedantic interest in and an obsessive knowledge of a specific topic ...1995 UK sl.
obsession - verbs
• BE LIKE A DOG WITH A BONE to be tenacious, persistent, or obstinate; to be unwilling to yield, relent, or let go; to be unable to set aside a preoccupation or obsession ...1887

OBSOLESCENT - verbs
• OBSOLESCE * to be obsolescent; to grow obsolete; to fall into disuse ...1873
 
OBSOLETE - adjectives
• ABOLETE †* obsolete, out of use ...c1515
• EXOLETE † that has gone out of use; disused, obsolete ...1611
• MODEL-T cheap, outdated; obsolete ...1938 Amer. sl.
• STEAM-POWERED obsolete ...1991 US sl. ​
obsolete - nouns 
• OBSOLETION * the act of becoming or condition of being obsolete; disuse, discontinuance ...1804
obsolete - verbs 
• OBSOLESCE * to be obsolescent; to grow obsolete; to fall into disuse ...1873
 
OBSTACLE - adjectives
• OBSTACULOUS †* of the nature of an obstacle ...a1643
obstacle - nouns 
• BACKHAUD an obstacle to progress ...1929 Sc.
• BALK † a ridge in the way, over which one may stumble; a stumbling-block, an obstacle ...1549
• BAR an obstruction, an obstacle; a barrier ...1531
• BAULK † a ridge in the way, over which one may stumble; a stumbling-block, an obstacle ...1549
• DILDERMOT an obstacle, a great difficulty ...Bk1900 Sc.
• FACER an unexpected problem or obstacle; anything to which one must face up ...c1820 sl.
• GAISHEN anything considered as an obstacle in one's way ...Bk1900 Sc.
• GAISHON anything considered as an obstacle in one's way; as the furniture of a house, etc. when in a disorderly state ...1808 Sc.
• IMPEACHMENT † hindrance, prevention, obstruction; impediment, obstacle ...1432
• LETTING delaying, hindering; a hindrance, an obstacle ...c1020 arch.
• LOSER a handicap; an obstacle, a disappointment ...c1920 sl.
• OBEX † an impediment, an obstacle ...1611 rare or obs. ​
• OBSTIC † an obstacle, objection ...1791 Sc.
• SNAG an impediment or obstacle; also, a disadvantage, a hitch; a defect ...1830
• SPANISH RADIO STATION used as the epitome of something that is always in the way ...1984 Trinidad & Tobago
• THRAW IN THE ROPE a snag, a hitch, a drawback; an unforeseen difficulty or obstacle in any undertaking ...1933 Sc.
obstacle - verbs
• KICK OUT THE JAMS to remove all obstacles, to fight for freedom ...1968 US sl.
• OPPONE † to set against by way of hindrance, check, or resistance; to place as an obstacle ...1570
• SUFFLAMINATE to put an obstacle in the way of, to obstruct ...1656 now rare
• UNCUMBER to free from encumbrance; to disencumber; to remove obstacles ...c1440
 
OBSTETRICIAN - see DOCTOR
 
OBSTETRICS - see PREGNANCY
 
OBSTINACY - nouns
• AWKWARDNESS perverseness, obstinacy, impracticability ...Bk1898 Eng. dial.
• AWKWARDS perverseness, obstinacy, impracticability ...Bk1898 Eng. dial.
• CAMSTEERINESS perversity, obstinacy ...1864 Sc.
• CAMSTRARINESS obstinacy, perversity ...1835 Sc.
• IMMORIGEROUSNESS † uncomplying obstinacy ...1649
• OBDURACY stubbornness, obstinacy; obstinate hardness of heart, relentlessness; persistence in evil ...1597
• OBDURATENESS stubbornness, obstinacy; obstinate hardness of heart, relentlessness; persistence in evil ...1618
• OBDURATION a hardening in sin or wickedness; a making or becoming stubborn, obstinate, or insensible or moral influence ...1494
• OBSTACLENESS † obstinacy ...1548
• OBSTINANCE * stubborn or self-willed persistence; obstinacy ...1432-50
• OBSTINANCY * stubborn or self-willed persistence; obstinacy ...1614
• OBSTINATION † obstinacy, stubbornness ...a1340
• OPINIASTRETY †* obstinate adherence to or maintenance of one's own opinion; stubbornness of mind ...1648
• OPINIASTRY † obstinate adherence to or maintenance of one's own opinion; stubbornness of mind ...a1643
• OPINIATRETURE †* obstinate adherence to or maintenance of one's own opinion; stubbornness of mind ...1699
• OPINIATRETY †* obstinate adherence to or maintenance of one's own opinion; stubbornness of mind ...1619
• OPINIATRY † obstinate adherence to or maintenance of one's own opinion; stubbornness of mind ...1651
• REEST restiveness; stubbornness; obstinacy, esp. of horses ...Bk1904 Eng. dial.
• SAND courage; tenacity; stamina; pluck; determination; perseverance; obstinacy ...1867 Amer. dial.
• TETCH obstinacy, restiveness ...1876 Eng. dial.
• THRAWNNESS perverseness, obstinacy, contrariness ...1890 Sc.
• UNBUXOMNESS † disobedience, obstinacy ...a1300
 
OBSTINATE - adjectives
• AFFECTIONATE † passionate, wilful, self-willed, headstrong, obstinate ...1542
• AFFECTIONED † passionate, wilful; self-willed, obstinate ...1582
• ANWILL † self-willed, stubborn, obstinate; persistently desirous, importunate ...c897
• ARSEWARD perverse, obstinate; unwilling ...1686 Eng. dial.
• ARSEWARDS perverse, obstinate; unwilling ...1686 Eng. dial.
• ASINARY † belonging to an ass; having the qualities characteristic of an ass; asinine, obstinate, stupid, doltish ...1731
• AWKWARD of persons or animals: perverse, obstinate, difficult to manage, bad-tempered ...1883 Eng. dial.
• BANDY impudent; obstinate ...Bk1911 Sc.
• BASTISH of persons: obstinate ...Bk1898 Sc.
• BASTOUS of persons: obstinate ...Bk1898 Sc.
• BUTT-HEADED headstrong, obstinate, bull-headed ..1908 Amer. dial.
• CAM perverse, obstinate, cross ...a1600 Eng. dial.
• CAMELISH obstinate as a camel ...Bk1888
• CAMSTARIE, CAMSTARY, CAMSTEERY, KAMSTEERY wild, mad, unmanageable, obstinate, perverse ...1776 Sc.
• CAMSTROUDGEOUS wild, unmanageable; obstinate, perverse ...1808 Sc.
• CAMSTRUDGEOUS wild; obstinate ...1933 Sc.
• CAPITOSE obstinate, headstrong ...1881
• CAT-WITTED small-minded, obstinate, and spiteful; silly and conceited; harebrained, whimsical ...1673
• COBBY headstrong, obstinate, arrogant, proud ...1785 Eng. dial.
• CONTRARY AS THE DEVIL'S OFF-HORSE perverse, uncooperative, stubborn, obstinate ...1940 Amer. dial.
• DERRY said of an obstinate person ...B1900 Eng. dial.
• DERRYBOUNDER said of an obstinate person ...B1900 Eng. dial.
• EVIL of persons: ill-tempered, cross, disagreeable, unpleasant, contentious, obnoxious, hostile, neurotic, angry, obstinate ...OE
• HAMMERHEADED stubborn, obstinate, hard-headed ...1954 Amer. dial.
• HARD-FACED impudent; obstinate; brazen-faced ...Bk1905 Eng. dial.
• HARD-HEADED † not easily led or persuaded; obstinate, stubborn ...1583 obs.
• HARD-HEADED AS MISCHIEF very headstrong or obstinate ...1986 Amer. dial.
• HARD IN THE MOUTH of people or horses: stubborn, obstinate ...1890 Eng. dial.
• HARD-MOUTHED self-willed, obstinate, stubborn ...1686
• HARD-NECKED † obstinate, stiff-necked ...1535
• HARD-NOLLED † obstinate, stiff-necked ...1388
• HARD-NOSED stubborn, obstinate, uncompromising ...1917 colloq.
• HARD-SET determined, obstinate ...1818
• HEAD-SET obstinate, headstrong ...1986 Amer. dial.
• HIGH-STOMACHED † haughty, disdainful, proud, obstinate, of high courage or spirit ...1548 obs. or arch.
• HOG-HEADED stupidly obstinate, pig-headed ...B1900 Eng. dial.
• IMMORIGEROUS † unyielding, obstinate; disobedient, rebellious; uncivil, rude ...1623
• KITTLE difficult to deal with, esp. because touchy, obstinate, or intractable; fickle, capricious ...Sc.
• LONG-HEADED stubborn, obstinate, pigheaded; detested ...1883 Amer. dial.
• NOTIONATE headstrong, obstinate, self-opinionated ...1871 Sc. & Amer. dial.
• OBDURATE hardened against persuasion, entreaty, the sentiment of pity, etc.; stubborn, obstinate, unyielding, inflexible, relentless, hard-hearted ...1586
• OBDURATIOUS †* hardened against persuasion, entreaty, the sentiment of pity, etc.; stubborn, obstinate, unyielding, inflexible, relentless, hard-hearted ...1672
​• OBDURE † hardened against persuasion, entreaty, the sentiment of pity, etc.; stubborn, obstinate, unyielding, inflexible, relentless, hard-hearted ...1624
• OBFIRMATION † the act of confirming or state of being confirmed in evil; stubbornness, obduracy ...1592
• OBSTACLE † obstinate, stubborn ...1536 obs. exc. Eng. dial. 
• OBSTINACIOUS * of an obstinate nature ...1830
• OBSTINED †* made obstinate or persistent; hardened ...1606
• OBSTRAPULOUS obstreperous; unmanageable, unruly; refractory, obstinate ...1830 Sc.
• OBSTROPALOUS obstreperous; unmanageable, unruly; refractory, obstinate ... c1725
• OBSTROPILOUS obstreperous; unmanageable, unruly; refractory, obstinate ...1830 Eng. dial.
• OBSTROPOLOUS obstreperous; unmanageable, unruly; refractory, obstinate ...1748
• OBSTROPULOUS obstreperous; unmanageable, unruly; refractory, obstinate ...1815 Eng. & Amer. dial.
• OFF-HORSEISH obstinate; odd, eccentric ...1967 Amer. dial.
• OILY mean-tempered; tough, mean, unpleasant, troublesome, unruly, obstinate ...1936 Amer. dial.
• ONWIL † self-willed, stubborn, obstinate; persistently desirous, importunate ...c897
• ONWILL † self-willed, stubborn, obstinate; persistently desirous, importunate ...c897
• OPINIATE † obstinately attached to one's opinion; opinionated ...1597
• OPINIATED obstinately attached to one's opinion; opinionated ...1597
• OPINIATIVE * stiff in opinion; adhering obstinately to one's own opinion; opinionative ...1574
• OPINIATORY † adhering obstinately to one's own opinion; opinionative ...1626
• OPINIATRED † obstinately attached to one's opinion; opinionated ...1641
• OPINIONATE † unduly attached to one's own opinion; obstinate in belief; opinionated ...1576
• OPSTROPOLOUS obstreperous; unmanageable, unruly; refractory, obstinate ...1830 Eng. dial.
• ORDINARY unpleasant, troublesome, unruly, obstinate, ill-tempered ...1800 Amer. dial.
• ORNERY unpleasant, troublesome, unruly, unmanageable, disobedient, obstinate, ill-tempered, angry ...1862 Amer. dial.
• OWLY adj. obstinate ...1965 Amer. dial.
• PERSNICKERTY fussy, finicky, particular, meticulous, precise; crotchety, cranky; disagreeable, obstinate ...1965 Amer. dial.
• PERSNICKETY disagreeable, cranky, crotchety; obstinate ...1905 Amer. dial.
• RAMSTRANG headlong, obstinate, stiff-necked ...Bk1905 Eng. dial.
• REESTY of a person: obstinate, bad-tempered; stiff ...1715 Sc. & Eng. dial.
• REFRACTARIOUS †* obstinate, stubborn, perverse ...1624
• RESOLUTE obstinate, strong-headed; restive; generally used of a child or a horse ...1885 Eng. dial.
• RUMGUMPTIOUS pompous; violent and obstinate in opinion; forward, rash, bold, quarrelsome, out of humour; boisterous ...1790 Eng. dial.
• SAVIGEROUS fierce, savage, violent, powerful, ill-tempered, headstrong, obstinate, strong-willed ...1839 Amer. dial.
• SAVIGROUS fierce, savage, violent, powerful, ill-tempered, headstrong, obstinate, strong-willed ...1887 Amer. dial.
• SERGIVEROUS fierce, savage, violent, powerful, ill-tempered, headstrong, obstinate, strong-willed ...1910 Amer. dial.
• SERVIGOUS fierce, savage, violent, powerful, ill-tempered, headstrong, obstinate, strong-willed ...1883 Amer. dial.
• SERVIGROUS headstrong, strong-willed, obstinate, pugnacious ...1909 Amer. dial.
• SEVIGROUS fierce, savage, violent, powerful , ill-tempered, headstrong, obstinate, strong-willed ...1835 Amer. dial.
• SOT obstinate ...Bk1913-17 Amer. dial.
• STOMACHFUL strong-willed, stubborn, or obstinate
• STUFFY sulky, obstinate, ill-humoured ...Bk1896 Amer. sl.
• SURVIGEROUS fierce, savage, violent, powerful, ill-tempered, headstrong, obstinate, strong-willed ...1952 Amer. dial.
• SURVIGOROUS fierce, savage, violent, powerful, ill-tempered, headstrong, obstinate, strong-willed ...1974 Amer. dial.
• SURVIGROUS fierce, savage, violent, powerful, ill-tempered, headstrong, obstinate, strong-willed ...1913 Amer. dial.
• SUVIGROUS fierce, savage, violent, powerful, ill-tempered, headstrong, obstinate, strong-willed ...1893 Amer. dial.
• TANGLESOME discontented; obstinate; fretful ...1823 Eng. dial.
• TARTUFFISH † sour, sullen, sulky, stubborn, obstinate ...B1900 Sc.
• TESTIF † headstrong, obstinate, wilful, rash, testy ...c1374
• THAWART cross, crabbed; obstinate; forward ...1901 Sc. & Eng. dial.
• THIRTOVER cross, contrary, obstinate, morose, ill-tempered, unruly, self-willed ...1852 Eng. dial.
• THRAWN perverse, obstinate; cross-grained; rebellious; morally wrong ...1737 Sc.
• THURTIFER cross, contrary, obstinate, morose, ill-tempered, unruly, self-willed ...1852 Eng. dial.
• THURTOVER cross, contrary, obstinate, morose, ill-tempered, unruly, self-willed ...1852 Eng. dial.
• THWARTOVER cross, contrary, obstinate, morose, ill-tempered, unruly, self-willed ...1852 Eng. dial.
• TOP-THRAWN headstrong, perverse, obstinate, wrong-headed ...1808 Sc.
• UNBELIEVING of a child: disobedient, unruly, obstinate, heedless ...Bk1893 Eng. dial.
• UNBIDDABLE perverse, obstinate, intractable, not to be advised ...1825 Sc.
• UNBOWSOME † obstinate; intractable ...c1290 obs. exc. Eng. dial.
obstinate - person
• AUGHT an obstinate, ill-conditioned child ...1768 Sc.
• BAD AUGHT an obstinate, ill-conditioned child ...1825 Sc.
• BITCH KITTY an obstinate, disagreeable, or bad-tempered girl or woman; a difficult, irritable, complaining woman ...c1930 Amer. sl.
• BITTER-ENDER one who fights or holds out to the bitter end; one who refuses yield, give way, or compromise; an obstinate person ...1850 colloq.
• CAMSTAIRY an obstinate, unmanageable person ...1818 Sc.
• HAMMERHEAD one who is stubborn, obstinate ...1975 Amer. dial.
• HARDHEAD an obstinate or stupid person ...1519
• IMPRACTICABLE an obstinate or stubborn person ...1829 
• LONGHEAD (derogatory) an obstinate, mule-headed person ...1986 Amer. dial.
• MULE an obstinate person ...Bk1913-17 Amer. dial.
• OPINIASTRE † a person obstinately attached to his own opinion; an opinionated person ...1603
• OPINIATOR † one who holds or maintains an opinion; one who obstinately adheres to his opinion; an opinionated person ...1523
• OPINIATRE † a person obstinately attached to his own opinion; an opinionated person ...a1677
• OPINIONATIST † an opinionated person; an obstinate dogmatist ...1634
• PEBBLE a troublesome or obstinate person or animal ...1829 colloq., chiefly Aust.
• PIG (derogatory) a boorish, coarse, obstinate, or disagreeable person ...1546
• PIGHEAD an obstinate person ...Bk1991 Amer. sl. 
• RAM-HEAD † one who has a head like a ram; a dull, thick-witted, obstinate person; a stupid person, a blockhead ...1605
• REESTER a wayward, obstinate person ...1887 Eng. dial.
• STIFFRUMP † an obstinate or haughty person ...1709 sl.
• THRAW-MULE a perverse and obstinate person ...Bk1905 N. Ireland
• THRAWN-STICK a queer, obstinate person ...1893 Sc.
• WIDDIE a very perverse or obstinate person ...1886 Sc.
• WUDDY a very perverse or obstinate person ...1886 Sc.
obstinate - verbs
• BE LIKE A DOG WITH A BONE to be tenacious, persistent, or obstinate; to be unwilling to yield, relent, or let go; to be unable to set aside a preoccupation or obsession ...1887
• OBDURATE to harden in wickedness, or against moral influence, etc.; to make stubborn or obstinate; to harden the heart of, to make relentless or pitiless ...a1540
• OBDURE † to harden in wickedness, or against moral influence, etc.; to make stubborn or obstinate; to harden the heart of, to make relentless or pitiless ...1598 rare or obs.
• OBFIRM † to confirm (in an evil course, erroneous opinion, etc.); to make stubborn or obstinate; to harden ...1563-87
• OBFIRMATE †* to confirm (in an evil course, erroneous opinion, etc.); to make stubborn or obstinate; to harden ...1616
• OPINIATRE † to persist obstinately in an opinion, or in a course of action; to insist hard; to become obstinate or stubborn ...1678
• OPINIONATE † to become or be opinionated or obstinate ...1603
• TAKE THE THRAW to take an obstinate fit ...1901 Sc.
• TEEL to be obstinately set or determined on doing anything ...1873 Eng. dial.
• TETCH to be obstinate or restive ...Bk1905 Eng. dial.
 
OBSTINATELY - adverbs
• OPINATIVELY † in an opinionated manner; with obstinate adherence to opinion ...1533
• OPINIATEDLY with obstinate adherence to opinion; in an opinionated manner ...1651
• OPINIATELY † with obstinate adherence to opinion; in an opinionated manner ...1658
• OPINIATIVELY with obstinate adherence to opinion; in an opinionated manner ...1600
• OPINIONATELY † in an opinionated manner, obstinately ...1647
 
OBSTREPEROUS - adjectives
• ABSTREPOLOUS obstreperous; noisy and difficult to control ...c1725
• ABSTREPULOUS obstreperous; noisy and difficult to control ...c1725
• LOBSTROPOLOUS obstreperous, loud, noisy, mischievous ...1891 Eng. dial.
• MAROONJUS harsh, stern; outrageous; obstreperous, ...1864 Sc.
• MORUNGEOUS harsh, stern; outrageous; obstreperous, ...1864 Sc.
• OBSTRACKLOUS obstreperous, wayward, masterful ...Bk1905 Eng. dial.
• OBSTRAPULOUS obstreperous; unmanageable, unruly; refractory, obstinate ...1830 Sc.
• OBSTREPOLOUS obstreperous; noisy and difficult to control ...c1725
• OBSTREPULOUS obstreperous; noisy and difficult to control ...c1725
• OBSTRIPEROUS obstreperous; disorderly, unruly ...M18 sl.
• OBSTROCULOUS obstreperous; noisy and difficult to control; disorderly, unruly...1930s Aust. sl.
• OBSTROPALOUS obstreperous; noisy and difficult to control ...c1725
• OBSTROPEROUS obstreperous; disorderly, unruly ...M18 sl.
• OBSTROPILOUS obstreperous; unmanageable, unruly; refractory, obstinate ...1830 Eng. dial.
• OBSTROPOLIS obstreperous; disorderly, unruly ...M18 sl.
• OPSTROPOLOUS obstreperous; unmanageable, unruly; refractory, obstinate ...1830 Eng. dial.
• OBSTROPULOUS obstreperous; noisy and difficult to control ...1815 Amer. dial.
• OBTREPERLOUS obstreperous; noisy and difficult to control ...c1725
• OBTROPOLOUS obstreperous; disorderly, unruly ...M18 sl.
• OUTSTROPOLOUS † outrageous, unruly, obstreperous ...1832 Sc.
• POLRUMPTIOUS restive, rude, unruly, obstreperous; foolishly confident ...1790 Eng. dial.
• RAMBUMPTIOUS noisy and unruly; boisterous; forward; obstreperous ...1911 Amer. dial.
• RAMBUNKSHUS noisy and unruly; boisterous; forward; obstreperous ...1866 Amer. dial.
• RAMBUNKSIOUS noisy and unruly; boisterous; forward; obstreperous ...1904 Amer. dial.
• RUMBUSTICAL fond of rough play; careless of the comfort of others; boisterous, unruly, uproarious, noisy, obstreperous;  rude, overbearing, violent ...1795 Eng. dial. & colloq.
• UPSTROPOLIS obstreperous; noisy and difficult to control ...1977 Amer. dial.
• UPSTROPPELOUS obstreperous; noisy and difficult to control ...1795 Amer. dial.
obstreperous - verbs 
• COME THE CUNT to be particularly obstreperous or unpleasant ...1984 UK sl.
• COME THE OLD CUNT to be particularly obstreperous or unpleasant ...1984 UK sl.
• RALLY to have a good time; to act utterly madly, drunkenly, or obstreperously; to party ...1960s US college sl.
 
OBSTREPEROUSNESS - nouns
• OBSTRAPULOSITY obstreperousness, restiveness, resistance ...1828 Sc.
 
OBSTRUCT - person
• GLAZIER a person who is obstructing one's view, etc. ...1738
obstruct - verbs
• ACCLOY to block, to obstruct, to clog, to choke ...c1430 
• BAFFLE to impede, to obstruct, to thwart, to balk ...1895 Eng. dial.
• BOFFLE to impede, to obstruct, to thwart, to balk ...1895 Eng. dial.
• DAIDLE to hinder or obstruct ...1910 Sc.
• DISASSIST †* to do the reverse of assisting; to hinder, to obstruct ...1669
• GILL POKE, JILL POKE to run into an obstruction; to puncture, poke, or known down ...1950 Amer. dial.
• HAGGLE to advance with difficulty; to do anything with much obstruction, to struggle ...1875 Sc. & Eng. dial.
• IMPEDIMENT † to put an impediment or obstruction in the way of; to obstruct ...1610
• LET to hinder, to prevent, to obstruct, to stand in the way of ...c888 arch.
• OBTURATE to stop up, to close, to obstruct ...1657 
• OBVARICATE †* to hinder, obstruct or stop one in his passage ...1623
• OPPONE † to endeavour to hinder, thwart, or overthrow; to withstand, to resist, to combat; to stand in the way of, to obstruct ...1610
• REMORATE †* to detain, delay, hinder, obstruct ...1638
• SCOTCH to block, to obstruct ...1966 Amer. dial.
• SUFFLAMINATE * to put an obstacle in the way of, to obstruct ...1656
 
OBSTRUCTED - adjectives
• HARROWED beaten, overcome, brought to a standstill; obstructed by an impediment or obstacle ...1890 Eng. dial.
• IMPEDIBLE † that can be impeded, obstructed, or hindered ...1655
• IMPEDITE † impeded, obstructed, hindered; having an impediment, defective ...1544
• OBTURATE †* stopped up, obstructed; fig. impervious ...c1560
obstructed - verbs
• GUNGE UP to become obstructed or clogged up ...1976 sl.

OBSTRUCTION - nouns
• ALBATROSS a source of frustration, obstruction, or guilt, from which it is difficult to rid oneself; a burden, an encumbrance; a hindrance ...1883
• ALBATROSS AROUND ONE'S NECK guilt, the haunting past, an unforgettable problem; a source of frustration or obstruction; a burden, an encumbrance; a hindrance ...1883
• BAR an obstruction, an obstacle; a barrier ...1531
• BARRACE †* a hindrance, obstruction, delay ...1480
• BARRICADO any barrier or obstruction to passage ...1611
• HANDERMENT obstruction, delay, hindrance ...Bk1905 Eng. dial.
• IMPEACHMENT † hindrance, prevention, obstruction; impediment, obstacle ...1432
• MAR † a hindrance, obstruction; an impediment in speech ...a1300
• OBTURATION the act of stopping up; obstruction of an opening or channel ...1610 
• OBVARICATION †* a hindering or obstructing one in his passage ...1658
• OFFENCE † obstruction, opposition ...1600
• TARRIER † one who or that which delays someone; a hinderer, an obstructor; an obstruction ...1614
• TIE an impediment, an obstruction ...1885 Eng. dial.
• UPSET a cross; an obstruction ...1839 Eng. dial.
 
OBSTRUCTIVE - adjectives
• IMPEDIENT obstructive, hindering, impeding ...1596
• IMPEDIMENTAL of the nature of an impediment; obstructive; impeding ...1654
• IMPEDIMENTARY of the nature of an impediment; obstructive; impeding ...1888
• IMPEDITIVE tending to impede or obstruct; obstructive ...1651
obstructive - person
• NARK an annoying, unpleasant, obstructive, or quarrelsome person ...1846 sl.
• NOAH'S ARK an annoying, unpleasant, obstructive, or quarrelsome person ...1941 rhyming sl. for 'nark'
obstructive - verbs 
• COME THE OLD TIN SOLDIER to be impertinent or obstructive ...1977 UK sl.
• COME THE TIN SOLDIER to be impertinent or obstructive ...1977 UK sl.
 
OBTAIN - adjectives
• IMPETRANT † that impetrates or obtains ...1624
obtain - nouns 
• AFFECTATION † a striving after, aiming at; a desire to obtain, earnest pursuit ...1549
obtain - person
• ANGLER a person who seeks to obtain or 'angles' for something ...1622
obtain - verbs 
• ABCAP to get, to obtain ...M19 UK criminal's sl.
• AFFECT † to aim at, to aspire to, to make for; to seek to obtain or attain ...1483
• BACK-DOOR to obtain without authorization ...a1989 US military sl.
• BAG to seize for oneself; to grab; to obtain ...1818 sl.
• BE HEART AND HAND FOR A THING to be eagerly bent on accomplishing or obtaining a thing ...Bk1902 Eng. dial. 
• CADGE to obtain by begging; to beg ...1811 sl.
• CAPTATE † to catch at, to strive to obtain, to seek after ...1628
• CATCH † 1. to receive, to get, to obtain ...c1205
† 2. to obtain by exertion; to attain, to get possession of ...1382
• CHASE UP to make efforts to find or obtain quickly ...1950s sl.
• CLIP to obtain (money) by deception or cheating sl.
• COP of objects: to obtain, to purchase, to acquire ...M19 sl.
• DIG OUT to research and discover; to find and obtain ...1611 UK sl.
• DIG UP to research and discover; to find and obtain ...1611 UK sl.
• ETTLE to attempt, to endeavour; to strive after, to struggle hard to obtain ...1725 Sc.
• FAKE A PICTURE to obtain an effect by some adroit, unorthodox means ...c1860 artistic usage
• FALL to have fall to one's share; to obtain, to win, to gain ...1641 Sc. & Eng. dial.
• FALL INTO to come upon, to obtain ...1930s
• FANG † to get, to obtain, to procure; also, to get together; to collect ...1340-70
• FANIGGLE to wangle, to manoeuvre, to obtain by devious means ...1930s Amer. dial.
• FINAGLE to wangle, to manoeuvre, to obtain by devious means; to get or achieve by trickery, craftiness, or persuasion ...1922 Amer. dial.
• FINAGLE AROUND to wangle, to manoeuvre, to obtain by devious means ...1930 Amer. dial.
• GAFF to get hold of ...1905 Amer. dial.
• GET THE HARE'S FOOT TO LICK to obtain very little ...1818
• HOCK to get hold of, to obtain ...1960s NZ sl.
• HUSTLE to obtain after a diligent effort, especially one using unorthodox, if not illegal means ...1840 US sl.
• IMPETRATE to obtain by request or entreaty; to procure ...1533-4
• IMPORT † to obtain, to gain, to win a victory ...1598
• MOOCH to obtain, as by begging, to beg; also, to steal ...1857 Amer. sl.
• MUMP to obtain by begging ...L17 sl.
• NAB to obtain for oneself; to grab ...M19 US sl.
• NAIL to take or obtain for oneself; to secure; to make sure of ...1732 sl., orig. criminals' usage
• OBSEEK †* to seek to obtain ...1646
• OFGO † to gain, to win, to obtain; to obtain by merit, to deserve, to earn ...c1000
• OFSERVE † to deserve, to merit; to obtain by deserving; to earn ...a1225
• PROMOTE in the circus or carnival: to obtain illegally something that is badly needed ...1980 US sl.
• PULL IT OFF to accomplish or obtain, esp. something remarkable, unique, or outrageous ...Bk1974 Amer. sl. 
• PULL OFF to accomplish or obtain, esp. something remarkable, unique, or outrageous ...1887 UK sl.
• QUARRY to obtain or extract by laborious methods ...1860 
• RAISE to obtain, to get hold of ...20C sl.
• RAME † to obtain by persistent asking ...1500-20 Sc.
• SCAINGE to obtain anything by long and serious effort; generally used in a bad sense ...Bk1904 Eng. dial.
• SCARE TOGETHER to obtain, usually with some difficulty and possibly by threatening the supplier ...M19 US sl.
• SCARE UP to obtain with effort ...colloq.
• SCORE to obtain something desired, esp. to purchase an illegal drug ...1914 colloq.
• SCRINCH to obtain with difficulty ...Bk1904 Eng. dial.
• SHARP to obtain by swindling, to steal ...L17 colloq.
• SNAFFLE to seize for oneself; to grab; to obtain ...1902 sl.
• SNAKE to get or obtain a thing furtively or surreptitiously; to steal or pilfer; to cheat a person out of something ...a1861
• SUIT † to aim at; to seek to obtain ...1559-60 Sc.
• TAIN †* to obtain, to get ...1501
• TAKE † to infer, to deduce; to obtain as a result ...c1380
• TAKE OFF to obtain, such as money ...1960s US Black & criminals' sl.
• TAKE OUT † to obtain or enjoy completely ...1631
• TILL † to labour after, to seek after, to provide; to get by effort, to obtain, acquire or earn by labour; later, to get, to obtain ...a900
• UMBRACE †* to surround; to obtain ...c1350
• WANGLE to obtain something by deceitful or devious means ...1888 sl., orig. printers' usage
 
OBTAINABLE - adjectives
• HAVEABLE * that can be had; obtainable ...a1641
 
OBTAINED - adjectives
• ACQUISITE † acquired; gained, gotten, obtained for oneself ...1532
• CHERCHED scrounged, obtained ... World War I Amer. sl.
• IMPETRABLE † that may be obtained ...1616
• IMPETRATE † obtained by request, esp. by application to an authority ...1528
• OBTENT † obtained, procured ...1432-50
• UNHAD not yet obtained ...Bk1905 Eng. dial.
obtained - nouns
• EASY LAY anything that is easily obtained ...1920s sl.
• INTAKE gain, profit; anything gathered in or obtained ...Bk1902 Eng. dial.
• MONEY FROM HOME something easily obtained ...Bk1913 Amer. dial. ​
 
OBTAINING - adjectives
• IMPETRATIVE * having the quality of obtaining by or as by request ...1612-15
• IMPETRATORY having the quality of obtaining by or as by request ...1612-15
• OBREPTITIOUS characterized by obreption; containing a false statement made for the sake of obtaining something ...1611
 
OBTAINING - nouns  (includes OBTAINMENT)
• ADEPTION † an obtaining, gaining, or attainment ...1548
• IMPETRATION the act of obtaining or procuring by request or entreaty ...1518
• OBREPTION the obtaining or trying to obtain something by craft or deceit ...1611
• OBTAINAL * obtainment ...1803
• OBTAINANCE * obtainment ...1846
• OBTENTION the act of obtaining; obtainment ...1624 
• WANGLE an act of obtaining deceitfully ...1915 sl.
 
OBVIOUS - adjectives
• BREME † brilliant, shining, bright; hence, clearly seen, evident, apparent, obvious ...c1340
• CONSPECTABLE †* easy to be seen; obvious ...1730
• EYELY †* visible or apparent to the eye; evident, obvious ...1561
• ILLUSTRIOUS † clearly manifest, evident, or obvious ...1654
• KENABLE obvious, easily recognizable ...1891 Sc.
• LIKE A COUNTRY DUNNY glaringly obvious, standing out ...1954 Aust. sl.
• OB obvious ...1980s sl.
• PALPABLE easily perceived; open to recognition; plain, evident, apparent, obvious, manifest ...1545
• PLAIN AS A PACKSTAFF, AS † a plain as a pikestaff, quite obvious and unmistakable ...1542
• PLAIN AS PARRITCH self-evident, obvious to all, as clear as crystal (parritch = porridge) ...1761 Sc.
• PLAIN AS THE BALLS ON A TALL DOG very obvious ...1967 US sl.
• PLAIN AS THE NOSE ON ONE'S FACE perfectly plain or obvious ...1655
• SOD-OFF very obvious ...2000 UK sl.
• STANDS OUT LIKE A BLACK CROW IN A BUCKET OF MILK obvious, extremely clear ...Bk1999 Aust. sl.
obvious - nouns 
• VISIBILITY an obvious fact, something apparent ...1834 Sc.
obvious - verbs 
• SEE THROUGH A LADDER to see what is obvious ...1852
obvious - phrases
• IF YOUR AUNT HAD BALLS, SHE'D BE YOUR UNCLE used as a rejoinder to a speaker who has just finished a long and laborious explanation of the obvious ...20C sl.
• IF MY AUNT HAD BEEN A MAN, SHE'D HAVE BEEN MY UNCLE used as a rejoinder to a speaker who has just finished a long and laborious explanation of the obvious ...M17 sl.
• NOT ABLE TO SEE BEYOND THE END OF ONE'S NOSE not able to see the most obvious things ...c1950 Amer. dial.
 
OBVIOUSLY - adverbs
• PALPABLY so as to be felt, plainly seen, observed, etc.; clearly, obviously, manifestly ...1584
 
OCCASION - nouns
• ACHESOUN † occasion, reason, purpose, motive ...c1330
• KAISHIN occasion, reason, cause ...1908 Sc.
• KANT opportunity, occasion ...1929 Sc.
• OCCASIONET † a small occasion ...1592 nonce word
• OFFER an occasion, opportunity ...1848 Ireland
• TID a fit or favourable time of season; an opportunity, occasion ...1721 Sc. ​
• TOOM † time convenient or proper for doing something; opportunity, occasion ...a1300
occasion - verbs 
• ILLATE †* to bring upon, occasion, cause ...1533
• IMPORT † to bring about, to cause, to occasion; to involve as a consequence or result ...1550
 
OCCASIONAL - adjectives
• ANTRIN occasional, rare ...1785 Sc.
• AUNTERIN occasional, rare ...1785 Sc.
• DAIMEN rare, occasional ...1790 Sc.
• HAPPENING casual, chance, occasional ...1895 Sc.
• OCCASIONARY †* occasional, made for particular occasions ...1702
• POPPIN' occasional, casual, turning or popping up by chance ...1900 Sc.
 
OCCASIONALLY - adverbs
• AT THE EDGE OF A TIME from time to time, occasionally ...1898 Sc.
• AT TIMES AND AGAIN at various times, occasionally ...1864
• BETIMES occasionally, now and then ...1913 Amer. dial.
• BY TIMES occasionally ...1841 Eng. & Amer. dial.
• EFTSOON † from time to time, occasionally, repeatedly ...1398 obs. or arch.
• EFTSOONS † from time to time, occasionally, repeatedly ...1398 obs. or arch.
• EVERY FOOT ANON every now and then, at intervals ...1790 Eng. dial.
• EVERY-LIKE from time to time, every now and then, occasionally ...Bk1900 Eng. dial.
• EVERY ONCE AN OCCASION now and again, once in a while ...1953 Amer. dial.
• EVERY WHILE STITCH every now and then, at intervals ...Bk1900 Eng. dial.
• EVERY WHIP AND TRIP every now and then, at intervals ...Bk1900 Eng. dial.
• EVERY WHIP AND TURN every now and then, at intervals ...Bk1900 Eng. dial.
• EVERY WHIP AND WHILE every now and then, at intervals ...Bk1900 Eng. dial.
• EVERY WHIP'S WHILE every now and then, at intervals ...Bk1900 Eng. dial.
• EVERY WOKE AND JIT every now and then, at intervals ...Bk1900 Eng. dial.
• HAND AWHILE now and then ...Bk1905 Eng. dial.
• ODDLINS here and there, occasionally ...Bk1905 Eng. dial.
• ODDLY occasionally, now and then, here and there ...Bk1905 Eng. dial.
• ONCE AND AWAY now and again, at intervals, occasionally ...1890 Eng. dial.
• ONCE AND OCCASIONALLY now and again, once in a while ...1953 Amer. dial.
• ONCE IN A COON'S AGE seldom; occasionally ...Bk1942 Amer. sl.
• ONCE IN A DOG'S AGE seldom; occasionally ...Bk1942 Amer. sl.
• ONCE IN A MONTH OF SUNDAYS seldom; occasionally ...Bk1942 Amer. sl.
• ONCE IN A WAY seldom; occasionally ...Bk1942 Amer. sl.
• ONCE IN A WEEK OF SUNDAYS seldom; occasionally ...Bk1942 Amer. sl.
• ONCE IN OCCASION now and again, once in a while ...1953 Amer. dial.
• PASSINGLY † occasionally; temporarily ...1828 Sc.
• SEMI-OCCASIONAL seldom; occasionally ...Bk1942 Amer. sl.
• SEMI-OCCASIONALLY seldom; occasionally ...Bk1942 Amer. sl.
• TIDE-WISE † at times, now and then ...1611
• TIME AND TIME occasionally, from time to time ...1900 Eng. dial.
• UPON TIMES now and then, occasionally ...Bk1905 Eng. dial.
• YERNE † willingly, gladly; occasionally, wilfully ...c888
 
OCCASIONED - adjectives
• OCCASIONATE † occasioned, brought about ...1471

OCCIDENTAL - person
• BIG NOSE an Occidental ...1942 US sl.

OCCULT - adjectives
• SIBYLLINE oracular, occult, mysterious ...1817
• TALISMANIC magical, occult, potent ...1678
• TALISMANICAL magical, occult, potent ...1650
• TALISMANTIC magical, occult, potent ...1814 nonce word
occult - nouns 
• HIDDEN HAND a secret or occult influence, esp. of a malignant character
occult - person
• CABBALIST one skilled in mystic arts or learning - an occultist...a1592
occult - verbs 
• APPORT to produce or transport by supposedly occult means ...M20​
 
OCCUPANCY - nouns
• OCCUPANCE * occupancy, occupying ...1814
 
OCCUPATION - nouns
• DAILY DOZEN one's work, occupation ...1930s sl.
• FACULTY † that in which anyone is skilled; an art, trade, occupation, profession ...c1386 obs. exc. arch. ​
• GAFF a job, an occupation ...1910s sl.
• GAIT one's trade or occupation ...M19 US sl.
• GIG work; any job or occupation ...1950s Amer. sl.
• LURK a job or occupation ...1916 Aust. & NZ sl.
• NUMBER a job or occupation ...1948 sl.
• RACKET a job, an occupation, not necessarily illegal ...1891 sl.
• SITE a job or occupation ...1930 US nautical usage
• THRIFT work, occupation, employment, business ...1798 Sc.
occupation - person 
• HABERDASHER one who deals with something; one who engages in an activity or occupation ...1592
• IDLEMAN * one who has no occupation ...1832
• OCCUPATIONER † one engaged in an occupation ...1592 
 
OCCUPIED - adjectives/adverbs
• AGAIT of a person: going on with work; busy, occupied, engaged upon ...1865 Eng. dial.
• AGATE of a person: going on with work; busy, occupied, engaged upon ...1865 Eng. dial.
• HAND-BOUND fully occupied, very busy ...1856 Eng. dial.
• NEGOTIOUS †* fully or constantly occupied or busy ...1642
• OCCUPATE † occupied; taken into and held in possession ...1605
• SISEL † occupied, engaged ...c1325
• THRANG busy; occupied; absorbed in work, etc.; of work: pressing ...1788 Sc. & Eng. dial.
• THRONG busy; occupied; absorbed in work, etc.; of work: pressing ...1781 Sc. & Eng. & Amer. dial.
• YERN † earnestly occupied or engaged, busy about something ...a1300
occupied - nouns
• RAT-KILLING. whatever one is occupied with at the moment; present business, occupation, or work-at-hand; miscellaneous tasks ...1967 Amer. dial.
occupied - verbs 
• HAVE IN OCCUPATION † to be occupied or busied with ...a1340
 
OCCUPY - verbs
• OCCUPATE † to occupy ...1547
• OFSIT † to sit upon, to occupy, to repress ...c888
• TENT ABOUT to occupy oneself ...1888 Eng. dial.
 
OCCUPYING - adjectives
• OCCUPAND † occupying ...1567 Sc.
• OCCUPATIVE * characterized by occupying or being occupied ...1656
 
OCCUR - verbs
• BELAMP † to happen, to occur, to befall ...a1000
• BELIMP † to happen, to occur, to befall ...a1000
• COOK to occur, to happen, to take place ...1940s Amer. sl.
• CROP UP to occur or appear, esp. unexpectedly ...colloq.
• FALL to befall, to betide; to happen, to occur ...1743 Sc. & Eng. dial.
• FALL FORTH † to happen; to occur ...1604
• FALL INTO A PERSON'S HEART † to occur to him ...c1340
• HAP to happen, to come to pass, to occur, to chance ...1340-70 arch.
• OBVENE †* to occur, to befall, to happen ...1654
• SUCCEED † to happen, to come to pass, to take place ...1537
 
OCCURRENCE - nouns
• ACCIDENT † an occurrence, incident, event ...c1374
• BEFALLING happening, occurrence, event ...c1374
• BEING † occurrence, happening ...1624
• BETIDING † happening, occurrence ...c1374
• CASE † a thing that befalls or happens to anyone; an event, occurrence, hap, or chance ...a1225
• HAPMENT an event, an occurrence, esp. an ill event; a misfortune, an accident ...1842 Eng. dial.
• HAPPEN an accident; an occurrence ...1875 Eng. dial.
• HAPPEN-CHANCE a matter of casual occurrence ...Bk1905 Eng. dial.
• INSTANCE an event, occurrence; curiosity ...Bk1902 Eng. dial.
• OCCURRENCY †* an occurrence, that which occurs or presents itself ...1656
• OCCURRENT † something that occurs ore meets one; an event, an occurrence ...1538
• PARAPHERNALLY a long rambling story; a tedious rigmarole; any event, affair, occurrence ...1828 Sc.
• TIDING † something that happens; an event, incident, occurrence ...c1205 obs. or arch.
• TIMING † happening, occurrence; good or ill fortune; an event, an occurrence ...c1250
 
OCCURRING - adjectives
• OCCURRENT * that occurs or happens; occurring ...1535
• UNDERGROWING † arising, occurring ...a1440