Английский Этимологический словарь - ribald (n.)

- early 13c., "rascal, scoundrel," from O.Fr. ribalt, from riber "be wanton, sleep around," from a Gmc. source (cf. O.H.G. riban "be wanton," lit. "to rub," possibly from the common euphemistic use of "rub" words to mean "have sex"), from P.Gmc. *wribanan. The adj. is 1500, from the noun.