Old English lustful "wishful, desirous, having an eager desire;" see lust (n.) + -ful. Specifically of immoderate sexual desire from 1570s. Related: Lustfully; lustfulness. Formerly also "vigorous" (1560s), a sense now given to lusty. Middle English also had lustsome, which was used in a sense of "voluptuous, lustful" from c. 1400, and lustly "pleasant," also "lustful." Old English had lustbære "desirable, pleasant, cheerful, joyous."