partner vs spouse equivalent

partner and spouse equivalent both are nouns.

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

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

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

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

partner (noun)	spouse equivalent (noun)
an associate in an activity or endeavor or sphere of common interest	a person (not necessarily a spouse) with whom you cohabit and share a long-term sexual relationship
a person's partner in marriage
a person who is a member of a partnership

partner (verb)	spouse equivalent (verb)
provide with a partner
act as a partner