Origin: Latin suffix -ate
Roommate has 2 different meanings across 1 category:
A person with whom one shares a room, as at university etc.
"After moving into the dormitory, Sarah quickly made her new roommate feel welcome by showing them around their shared bedroom."
In plain English: A roommate is someone you live with and share your house or apartment, usually splitting costs for rent and utilities.
"My roommate usually cooks dinner on weekends so we can share the cost."
Usage: A roommate is specifically the other occupant of your living space, not just someone you live near or share expenses with generally. Use this term to describe any cohabiting partner in a shared housing arrangement, regardless of whether they are family members or strangers.
The word roommate is a straightforward combination of the words room and mate. It was formed to describe two or more people who share living quarters together.