endogamy vs matrimony

endogamy and matrimony both are nouns.

Word	Noun	Adjective	Verb	Adverb
endogamy	Yes	No	No	No
matrimony	Yes	No	No	No

As nouns, matrimony is a hypernym of endogamy; that is, matrimony is a word with a broader meaning than endogamy:

endogamy: marriage within one's own tribe or group as required by custom or law
matrimony: the state of being a married couple voluntarily joined for life (or until divorce)

Other hypernyms of endogamy include marriage, spousal relationship, union, wedlock.

endogamy (noun)	matrimony (noun)
marriage within one's own tribe or group as required by custom or law	the ceremony or sacrament of marriage
	the state of being a married couple voluntarily joined for life (or until divorce)