c.1300 (trans.), "to turn someone aside from a right religious belief to a false or erroneous one," from O.Fr. pervertir, from L. pervertere "corrupt, turn the wrong way, turn about," from per- "away" + vertere "to turn" (see versus). The noun is 1661, from the verb. Replaced native froward, which embodies the same image. The noun is attested from 1661, "one who has forsaken a doctrine or system regarded as true, apostate;" psychological sense of "one who has a perversion of the sexual instinct" is attested from 1897 (Havelock Ellis), originally esp. of homosexuals. Perv, short for sexual pervert (n.), is first recorded 1944.