unfaithful vs apostate

unfaithful is not a noun while apostate is a noun.

Word	Noun	Adjective	Verb	Adverb
unfaithful	No	Yes	No	No
apostate	Yes	Yes	No	No

unfaithful (noun)	apostate (noun)
	a disloyal person who betrays or deserts his cause or religion or political party or friend etc.

unfaithful (adjective)	apostate (adjective)
not true to duty or obligation or promises	not faithful to religion or party or cause
having sexual relations with someone other than your husband or wife, or your boyfriend or girlfriend
having the character of, or characteristic of, a traitor
not trustworthy