BEING A MOST SURPRISING AND INSTANTANEOUS WORD, OF UNEXPECTED ORIGIN
adj. — sudden
fm. Latin, repentinus, meaning sudden, and Middle French, repentin, meaning sudden. Notably not from the same root words that give us “repent” (from the Latin/French paenitens, for penitent, meaning to repent), “repentine” is still often associated with religion.
first published. 1487
“The[se] repentine…mischiefs sting before they hiss.”
—Thomas Adams, clergyman, 1633
inspiration. The Oxford English Dictionary