mid-13c., "a rogue, ruffian, rascall, scoundrell, varlet, filthie fellow" [Cotgrave], from Old French ribalt, of uncertain origin, perhaps from riber "be wanton, sleep around," from a Germanic source (cf. Old High German riban "be wanton," literally "to rub," possibly from the common euphemistic use of "rub" words to mean "have sex"), from Proto-Germanic *wribanan, from PIE root *wer- (3) "to turn, bend" (see versus). The adjective is attested from c.1500, from the noun.