traitor vs double-crosser

traitor and double-crosser both are nouns.

Word	Noun	Adjective	Verb	Adverb
traitor	Yes	No	No	No
double-crosser	Yes	No	No	No

As nouns, traitor and double-crosser are synonyms defined as:

traitor and double-crosser: a person who says one thing and does another

Other synonyms of traitor include betrayer, double-dealer, two-timer.

traitor (noun)	double-crosser (noun)
someone who betrays his country by committing treason	a person who says one thing and does another
a person who says one thing and does another