bigamy vs marriage

bigamy and marriage both are nouns.

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

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

bigamy: the state of having two spouses at the same time
marriage: the state of being a married couple voluntarily joined for life (or until divorce)

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

bigamy (noun)	marriage (noun)
the offense of marrying someone while you have a living spouse from whom no valid divorce has occurred	the act of marrying; the nuptial ceremony
the state of having two spouses at the same time	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