bigamist vs spouse

bigamist and spouse both are nouns.

Word	Noun	Adjective	Verb	Adverb
bigamist	Yes	No	No	No
spouse	Yes	No	No	No

As nouns, spouse is a hypernym of bigamist; that is, spouse is a word with a broader meaning than bigamist:

bigamist: someone who marries one person while already legally married to another
spouse: a person's partner in marriage

Other hypernyms of bigamist include better half, married person, mate, partner.

bigamist (noun)	spouse (noun)
someone who marries one person while already legally married to another	a person's partner in marriage