c. 1300, "lascivious, lecherous, unchaste," from Old French luxurios "lustful, lascivious" (Modern French luxurieux), from Latin luxuriosus "immoderate, excessive; voluptuous; profuse," from luxuria "excess, profusion; extravagant living" (see luxury). Meaning "given to luxury, voluptuous" (of persons) is from c. 1600. Of things, "characterized by luxury," from 1640s. Related: Luxuriously; luxuriousness.