liaison

n. [ F., fr. L. ligatio, fr. ligare to bind. See Ligature, and cf. Ligation. ] 1. A union, or bond of union; an intimacy; an interrelationship. [ 1913 Webster ]

2. Specifically, An illicit sexual relation between a man and a woman; a sexual afffair. [ 1913 Webster ]

3. Specifically: A process of communication between parts of an organization or between two organizations acting together for a common purpose. [ PJC ]

4. Hence: A person whose function it is to maintain such communication. [ PJC ]

5. (Phonetics) A pronunciation of a consonant sound that would be otherwise silent, such as the final consonant of certain French words, when the following word begins with a vowel sound. [ PJC ]