intermarry vs intermarriage

intermarry is not a noun while intermarriage is a noun.

Word	Noun	Adjective	Verb	Adverb
intermarry	No	No	Yes	No
intermarriage	Yes	No	No	No

intermarry (noun)	intermarriage (noun)
	marriage within one's own tribe or group as required by custom or law
	marriage to a person belonging to a tribe or group other than your own as required by custom or law

intermarry (verb)	intermarriage (verb)
marry within the same ethnic, social, or family group