The Collaborative International Dictionary of English v.0.48:
double-crosser \double-crosser\ n. one who double-crosses another; a person who says one thing and does another. Syn: double-dealer, betrayer, traitor. [WordNet 1.5]WordNet (r) 3.0 (2006):
double-crosser n 1: a person who says one thing and does another [syn: double- crosser, double-dealer, two-timer, betrayer, traitor]