The Collaborative International Dictionary of English v.0.48:

Comrade \Com"rade\ (? or ?; 277), n. [Sp. camarada, fr. L.
   camara, a chamber; hence, a chamber-fellowship, and then a
   chamber-fellow: cf. F. camarade. Cf. Chamber.]
   A mate, companion, or associate.
   [1913 Webster]

         And turned my flying comrades to the charge. --J.
                                                  Baillie.
   [1913 Webster]

         I abjure all roofs, and choose . . .
         To be a comrade with the wolf and owl.   --Shak.
   [1913 Webster]

WordNet (r) 3.0 (2006):

comrade
    n 1: a friend who is frequently in the company of another;
         "drinking companions"; "comrades in arms" [syn:
         companion, comrade, fellow, familiar, associate]
    2: a fellow member of the Communist Party
    3: used as a term of address for those male persons engaged in
       the same movement; "Greetings, comrade!" [syn: brother,
       comrade]

Moby Thesaurus II by Grady Ward, 1.0:

94 Moby Thesaurus words for "comrade":
   Bolshevik, Bolshie, Greek, Red, ace, adjunct, affiliate, ally,
   amigo, associate, auxiliary, bedfellow, bedmate, belonger,
   bosom buddy, brother, brother-in-arms, buddy, bunkie, bunkmate,
   butty, camarade, card-carrier, card-carrying member, cardholder,
   chamberfellow, charter member, chum, classmate, clubber, clubman,
   clubwoman, coadjutor, cohort, colleague, comate, commie,
   committeeman, companion, company, compatriot, compeer, confederate,
   confrere, consociate, consort, conventioneer, conventioner,
   conventionist, copartner, crony, dues-paying member, enlistee,
   enrollee, fellow, fellow member, fellow student, fraternity man,
   friend, girl friend, gossip, guildsman, honorary member, initiate,
   insider, joiner, life member, mate, member, messmate, old crony,
   one of us, pal, pard, pardner, partner, playfellow, playmate,
   pledge, roommate, running mate, schoolfellow, schoolmate, shipmate,
   side partner, sidekick, sister, socius, sorority girl,
   sorority woman, teammate, workfellow, yokefellow, yokemate