Source : Webster's Revised Unabridged Dictionary (1913)

Contentious \Con*ten"tious\, a. [L. contentiosus: cf. F.
   contentieux.]
   1. Fond of contention; given to angry debate; provoking
      dispute or contention; quarrelsome.

            Despotic and contentious temper.      --Macaulay.

   2. Relating to contention or strife; involving or
      characterized by contention. --Spenser.

            More cheerful, though not less contentious, regions.
                                                  --Brougham.

   3. (Law) Contested; litigated; litigious; having power to
      decide controversy.

   {Contentious jurisdiction} (Eng. Eccl. Law), jurisdiction
      over matters in controversy between parties, in
      contradistinction to {voluntary jurisdiction}, or that
      exercised upon matters not opposed or controverted.

   Syn: Quarrelsome; pugnacious; dissentious; wrangling;
        litigious; perverse; peevish. -- {Con*ten"tious*ly},
        adv. -- {Con*ten"tious*ness}, n.

Source : WordNet®

contentious
     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: {disputatious},
             {disputative}, {litigious}]
     2: involving or likely to cause controversy; "a central and
        contentious element of the book"- Tim W.Ferfuson
     3: having or showing a ready disposition to fight; "bellicose
        young officers"; "a combative impulse"; "a contentious
        nature" [syn: {battleful}, {bellicose}, {combative}]