Wordnet 3.0
NOUN (1)
1. 
 a usually secretive or illicit sexual relationship; 
[syn: affair, affaire, intimacy, liaison, involvement, amour]
WordNet (r) 3.0 (2006):
affaire
    n 1: a usually secretive or illicit sexual relationship [syn:
         affair, affaire, intimacy, liaison, involvement,
         amour]