The Collaborative International Dictionary of English v.0.48:

Colloquy \Col"lo*quy\, n.; pl. Colloquies. [L. colloquium. See
   Collocution.]
   1. Mutual discourse of two or more persons; conference;
      conversation.
      [1913 Webster]

            They went to Worms, to the colloquy there about
            religion.                             --A. Wood.
      [1913 Webster]

   2. In some American colleges, a part in exhibitions, assigned
      for a certain scholarship rank; a designation of rank in
      collegiate scholarship.
      [1913 Webster]

WordNet (r) 3.0 (2006):

colloquy
    n 1: a conversation especially a formal one
    2: formal conversation

Moby Thesaurus II by Grady Ward, 1.0:

22 Moby Thesaurus words for "colloquy":
   chat, colloquial discourse, colloquium, communication, communion,
   confabulation, conversation, converse, conversing, dialogue,
   discourse, exchange, give-and-take, intercourse, interlocution,
   palaver, parley, rap session, rapping, seminar, talk,
   verbal intercourse