lover vs spousal equivalent

lover and spousal equivalent both are nouns.

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

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

lover: a significant other to whom you are not related by marriage
spousal equivalent: a person (not necessarily a spouse) with whom you cohabit and share a long-term sexual relationship

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

lover (noun)	spousal equivalent (noun)
a person who loves someone or is loved by someone	a person (not necessarily a spouse) with whom you cohabit and share a long-term sexual relationship
an ardent follower and admirer
a significant other to whom you are not related by marriage