exogamous vs exogamy

exogamous is not a noun while exogamy is a noun.

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

exogamous (noun)	exogamy (noun)
	marriage to a person belonging to a tribe or group other than your own as required by custom or law

exogamous (adjective)	exogamy (adjective)
pertaining to or characterized by the custom of marrying only outside the limits of a clan or tribe
characterized by or fit for fertilization by a flower that is not closely related