faithful vs unfaithful

faithful is a noun but unfaithful is not a noun.

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

faithful (noun)	unfaithful (noun)
a group of people who adhere to a common faith and habitually attend a given church
any loyal and steadfast following

faithful (adjective)	unfaithful (adjective)
steadfast in affection or allegiance	not true to duty or obligation or promises
not having sexual relations with anyone except your husband or wife, or your boyfriend or girlfriend	having sexual relations with someone other than your husband or wife, or your boyfriend or girlfriend
marked by fidelity to an original	having the character of, or characteristic of, a traitor
	not trustworthy