exogamy vs marriage

exogamy and marriage both are nouns.

Word	Noun	Adjective	Verb	Adverb
exogamy	Yes	No	No	No
marriage	Yes	No	No	No

As nouns, marriage is a hypernym of exogamy; that is, marriage is a word with a broader meaning than exogamy:

exogamy: marriage to a person belonging to a tribe or group other than your own as required by custom or law
marriage: the state of being a married couple voluntarily joined for life (or until divorce)

Other hypernyms of exogamy include matrimony, spousal relationship, union, wedlock.

exogamy (noun)	marriage (noun)
marriage to a person belonging to a tribe or group other than your own as required by custom or law	the act of marrying; the nuptial ceremony
	two people who are married to each other
	the state of being a married couple voluntarily joined for life (or until divorce)
	a close and intimate union