double-crosser vs slicker

double-crosser and slicker both are nouns.

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

As nouns, slicker is a hypernym of double-crosser; that is, slicker is a word with a broader meaning than double-crosser:

Other hypernyms of double-crosser include beguiler, cheat, cheater, deceiver, trickster.

double-crosser (noun)	slicker (noun)
a person who says one thing and does another	a macintosh made from cotton fabric treated with oil and pigment to make it waterproof
	someone who leads you to believe something that is not true
	a person with good manners and stylish clothing