verve (n.)

1690s, "special talent in writing, enthusiasm in what pertains to art and literature," from French verve "enthusiasm" (especially pertaining to the arts), in Old French "caprice, odd humor, proverb, saying; messenger's report" (12c.), probably from Gallo-Roman *verva, from Latin verba "(whimsical) words," plural of verbum "word" (see verb). Meaning "mental vigor" is first recorded 1803.