to behave as a peacock;
to flaunt one's appearance in a vain fashion; to strut ...1838 obs. rare
from Latin pāvōn-, pāvō peacock + -ize
FIRST DOCUMENTED USE
1838 - see EXAMPLE below
"...and, I must say, that I never could perceive any more "harmony and fascination" in the movements of the pavonizing gaditanas who frequent it, than in those of the fair promenaders of other Spanish towns..."
From: Excursions in the Mountains of Ronda and Granada
- Captain C. Rochfort Scott, Vol II