cabinmate
/ˈkæbɪnˌmeɪt/
noun
- A person who shares a cabin with another person, especially at a camp, on a ship, or in a dormitory.
- My cabinmate at summer camp snored so loudly that I could barely sleep.
- The cruise assigned us a random cabinmate, but we got along really well.
- She became best friends with her cabinmate during the week-long sailing trip.