1590s, "one who shares the same room," hence "a close companion," from Middle French camarade (16c.), from Spanish camarada "chamber mate," or Italian camerata "a partner," from Latin camera "vaulted room,
chamber" (see camera). In Spanish, a collective noun referring to one's company. In 17c., sometimes jocularly misspelled comrogue. Used from 1884 by socialists and communists as a prefix to a surname to avoid "Mister" and other such titles. Related: Comradely; comradeship.