Wielki słownik angielsko-polski red. nacz D. Jemielniak, M. Miłkowski

(Noun) prawniczy konkubent/konkubina;

Wordnet angielsko-polski

(a person (not necessarily a spouse) with whom you cohabit and share a long-term sexual relationship)
partner
synonim: domestic partner
synonim: significant other
synonim: spouse equivalent