unprofitable, profitless, unrewarding ...1650 obs. rare
from im- + proficuous (adj. profitable, beneficial, useful),
from Latin proficuus (profitable, advantageous, beneficial, useful) + -uus, (suffix forming adjectives) + -ous
FIRST DOCUMENTED USE
1650 - see EXAMPLE below
"...and as we prune luxurious Vines, so wee may take away and freely coerce that improficuous matter of Haire; nourishing of extraordinarie long Haire, having been ever infamous to Men in all ages..."
From: Anthropometamorphosis: Man Transform'd: or, The Artificiall Changling
- John Bulwer