The Collaborative International Dictionary of English v.0.48:

Disputation \Dis`pu*ta"tion\, n. [OE. desputeson, disputacion,
   OF. desputeison, F. disputation, fr. L. disputatio. See
   Dispute, v. i.]
   1. The act of disputing; a reasoning or argumentation in
      opposition to something, or on opposite sides; controversy
      in words; verbal contest respecting the truth of some
      fact, opinion, proposition, or argument.
      [1913 Webster]

   2. A rhetorical exercise in which parties reason in
      opposition to each other on some question proposed.
      [1913 Webster]

WordNet (r) 3.0 (2006):

disputation
    n 1: the formal presentation of a stated proposition and the
         opposition to it (usually followed by a vote) [syn:
         debate, disputation, public debate]
    2: a contentious speech act; a dispute where there is strong
       disagreement; "they were involved in a violent argument"
       [syn: controversy, contention, contestation,
       disputation, disceptation, tilt, argument, arguing]