The Collaborative International Dictionary of English v.0.48:

Disputatious \Dis`pu*ta"tious\, a.
   Inclined to dispute; apt to civil or controvert;
   characterized by dispute; as, a disputatious person or
   temper.
   [1913 Webster]

         The Christian doctrine of a future life was no
         recommendation of the new religion to the wits and
         philosophers of that disputations period.
                                                  --Buckminster.
   -- Dis`pu*ta"tious*ly, adv. -- Dis`pu*ta"tious*ness, n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

disputatious
    adj 1: inclined or showing an inclination to dispute or
           disagree, even to engage in law suits; "a style described
           as abrasive and contentious"; "a disputatious lawyer"; "a
           litigious and acrimonious spirit" [syn: contentious,
           combative, disputatious, disputative, litigious]