Wordnet 3.0
VERB (1)
1. 
 be sexually unfaithful to one's partner in marriage; 
- Example: "She cheats on her husband"- Example: "Might her husband be wandering?"[syn: cheat on, cheat, cuckold, betray, wander]
WordNet (r) 3.0 (2006):
cheat on
    v 1: be sexually unfaithful to one's partner in marriage; "She
         cheats on her husband"; "Might her husband be wandering?"
         [syn: cheat on, cheat, cuckold, betray, wander]