the person who you are living with and having a sexual relationship with but are not married to. The usual British word is partner.
Synonyms and related words
Words for people according to marital status
bachelor
Bridget Jones
couple
domestic partner
noun countable
US
Word Forms
singular
domestic partner
plural
domestic partners
DEFINITIONS1
1
the person who you are living with and having a sexual relationship with but are not married to. Domestic partners can be of the same sex or different sexes.