The Collaborative International Dictionary of English v.0.48:

Comradeship \Com"rade*ship\, n.
   The state of being a comrade; intimate fellowship.
   [1913 Webster]

WordNet (r) 3.0 (2006):

comradeship
    n 1: the quality of affording easy familiarity and sociability
         [syn: chumminess, camaraderie, comradeliness,
         comradery, comradeship]

Moby Thesaurus II by Grady Ward, 1.0:

54 Moby Thesaurus words for "comradeship":
   affiliation, alignment, alliance, amalgamation, association,
   boon companionship, brotherhood, brotherliness, cahoots,
   camaraderie, chumship, coadunation, coalescence, coalition,
   colleagueship, collegialism, collegiality, combination,
   community of interest, companionship, comradery, confederacy,
   confederation, confraternity, consolidation, consorting,
   consortship, copartnership, copartnery, esprit de corps,
   federation, fellowship, fraternalism, fraternity, fraternization,
   freemasonry, fusion, good-fellowship, hobnobbing, hookup,
   inclusion, incorporation, integration, league, merger, partnership,
   sisterhood, sisterliness, sodality, sorority, tie-in, tie-up,
   unification, union