Oxford English Dictionary, v. courtesan, -zan, 1, Obs., «One attached to the court of a prince»; courtesan, -zan, 2, «A court-mistress», Etymon «a. F. courtisane, ad. It. cortigiana, in Florio cortegiana «a curtezane, a strumpet», orig. woman attached to the court, fem. of cortigiano. In quotation 1565 directly from Italian»