n.1 communication or cooperation, esp. between military forces or units.
2 an illicit sexual relationship.
3 the binding or thickening agent of a sauce.
4 the sounding of an ordinarily silent final consonant before a word beginning with a vowel (or a mute h in French).
Phrases and idioms:
liaison officer an officer acting as a link between allied forces or units of the same force.
Etymology: F f. lier bind f. L ligare