live-in

1. not comparableLiving on the premises; usually said of a household employee or a domestic partner.

   A live-in maid is a true luxury, but even a maid once a week is great.

   1 more example

   The Air Force veteran fatally shot by police during last week’s US Capitol riot had been in a “throuple” with her husband and their live-in girlfriend, according to reports.

   2021 January 14, Tamar Lapin, “Ashli Babbitt, Air Force vet killed at Capitol, was in a ‘throuple’”, in New York Post, retrieved 22 Jul 2021

plural live-ins

1. A household employee or domestic partner who lives on the premises of the employer or partner.

   30, Camb seeks one man lover 20-32: shd lke domestic evenings, books, edc people, travel. Possible live-in for right guy.

   1974 February 2, “ATTRAC, WELL OFF HARV-ED GWM (personal advertisement)”, in Gay Community News, volume 1, number 32, page 14

   1 more example

   […] but that doesn't stop families from hiring live-ins; nor does it stop newly arrived Latina migrant workers from taking jobs they urgently need.

   2001, Pierrette Hondagneu-Sotelo, Doméstica, page 31

2. A firefighter who lives at the fire station.