double-dealer vs traitor

double-dealer and traitor both are nouns.

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

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

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

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