1. (noun)two-timer someone who deceives a lover or spouse by carrying on a sexual relationship with somebody else Synonyms: double-dealer, traitor, betrayer, double-crosser
2. (noun)double-crosser, double-dealer, two-timer, betrayer, traitor a person who says one thing and does another Synonyms: betrayer, double-crosser, blabber, traitor, double-dealer, squealer, two-timer, rat, informer, treasonist