late 14c., peyvesshe "perverse, capricious, silly," a word of uncertain origin; probably modeled on Latin perversus "reversed, perverse," past participle of pervertere "to turn about" (see pervert (v.)). Original sense was obsolete from 17c. The meaning "cross, fretful. ill-tempered" is recorded from 1520s. Related: Peevishly; peevishness.