betrayer

1 a person who provides information about another's wrongdoing the arrested drug dealer vowed that he would get his revenge on his betrayer Synonyms informer, canary [slang], deep throat, fink, informant, nark [British], rat, rat fink, snitch, snitcher, squealer, stoolie, stool pigeon, talebearer, tattler, tattletale, telltale, whistle-blowerRelated Words collaborator; blabber, blabbermouth, gossip, gossiper, leaker; snoop, snooper, spy; notifier

2 one who betrays a trust or an allegiance the betrayer of Anne Frank's family in Amsterdam has never been identified for certain Synonyms apostate, backstabber, traitor, double-crosser, double-dealer, Judas, quisling, recreant, serpent, snake, turncoatRelated Words accommodationist, collaborationist, collaborator, sellout, subversive, subverter; coconspirator, conspirator, intriguer, plotter, schemer; defector, deserter, renegade; blabbermouth, gossip, gossiper, gossipmonger, informant, informer, rat, rumormonger, snitch, snitcher, squealer, stool pigeon, talebearer, talker, tattler, tattletale, telltale