disputative

from WordNet (r) 3.0 (2006)

disputative
    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}]

from The Collaborative International Dictionary of English v.0.48

Disputative \Dis*put"a*tive\, a. [L. disputativus.]
   Disposed to dispute; inclined to cavil or to reason in
   opposition; as, a disputative temper. --I. Watts.
   [1913 Webster]