Nouns

(n)spouse, partner, married person, mate, better halfa person's partner in marriage
(n)collaborator, cooperator, partner, pardneran associate in an activity or endeavor or sphere of common interest“the musician and the librettist were collaborators”, “sexual partners”
(n)partnera person who is a member of a partnership

Verbs

(v)partnerprovide with a partner
(v)partneract as a partner“Astaire partnered Rogers”