a close or intimate companion

boyhood chums.

a roommate, as at college.

to associate closely.

to share a room or rooms with another, esp. in a dormitory at a college or prep school.

noun

enemy

noun

associate , bro , buddy , co-mate , companion , comrade , crony , mate , pal , playmate , sis , amigo , brother , confidant , confidante , familiar , intimate , fellow , friend , matey , pard , roommate , sidekick