spouse vs spousal equivalent

spouse and spousal equivalent both are nouns.

Word	Noun	Adjective	Verb	Adverb
spouse	Yes	No	No	No
spousal equivalent	Yes	No	No	No

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

spouse: a person's partner in marriage
spousal equivalent: a person (not necessarily a spouse) with whom you cohabit and share a long-term sexual relationship

Other hypernyms of spouse include domestic partner, significant other, spouse equivalent, relation, relative.

spouse (noun)	spousal equivalent (noun)
a person's partner in marriage	a person (not necessarily a spouse) with whom you cohabit and share a long-term sexual relationship