Know why cattywampus was trending last week?
Old English lustfull "wishful, desirous, having an eager desire;" see lust (n.) + -ful. Specifically of sexual desire from 1570s. Related: Lustfully; lustfulness. Middle English also had lustsome, which was used in a sense of "voluptuous, lustful" from c.1400. Old English had lustbære "desirable, pleasant, cheerful, joyous."