Webster’s Revised Unabridged Dictionary · 1913 Liaison Li′ai′son′ (lē′ā′zôN′), n. [F., fr. L. ligatio, fr. ligare to bind. See Ligature, and cf. Ligation.] A union, or bond of union; an intimacy; especially, an illicit intimacy between a man and a woman. ‹ Liage Liane ›