Webster’s Revised Unabridged Dictionary · 1913
Chum
Chum (chŭm), n. [Perh. a contraction fr. comrade or chamber fellow: cf. also AS. cuma a comer, guest.] A roommate, especially in a college or university; an old and intimate friend.
Chum, v. i. [imp. p. p. Chummed; p. pr. & vb. n. Chumming.] To occupy a chamber with another; as, to chum together at college. [U. S.]
Chum, n. Chopped pieces of fish used as bait. [U. S.]