Turncoats, being a slang term to describe someone who abandons a group or cause, has numerous synonyms in the English language. Some common synonyms for turncoat are traitor, renegade, defector, apostate, deserter, sellout, double-crosser, and backstabber. Other terms that can be used are betrayer, collaborator, informer, mutineer, rebel, and rat. Each of these synonyms can be used to describe someone who has departed from a group or cause and has switched their affiliations, loyalty, or beliefs to the opposition. Regardless of which synonym one chooses to use, the underlying connotation remains the same - to betray someone or something.