double-dealer vs double-crosser

double-dealer and double-crosser both are nouns.

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

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

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

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

double-dealer (noun)	double-crosser (noun)
a person who says one thing and does another	a person who says one thing and does another