1590s, "immodest, wanton, saucy," from French petulant (mid-14c.), from Latin petulantem (nominative petulans) "wanton, froward, saucy, insolent," present participle of petere "to attack, assail; strive after; ask for, beg, beseech" (from PIE root *pet- "to rush, to fly"). Meaning "irritable, manifesting peevish impatience" is by 1775, probably by influence of pet (n.2). Related: Petulantly.
updated on May 11, 2020