The Collaborative International Dictionary of English v.0.48:

Contradictory \Con`tra*dict"o*ry\, n.; pl. Contradictories.
   1. A proposition or thing which denies or opposes another;
      contrariety.
      [1913 Webster]

            It is common with princes to will contradictories.
                                                  --Bacon.
      [1913 Webster]

   2. pl. (Logic) propositions with the same terms, but opposed
      to each other both in quality and quantity.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Contradictory \Con`tra*dict"o*ry\, a. [LL. contradictorius: cf.
   F. contradictoire.]
   1. Affirming the contrary; implying a denial of what has been
      asserted; also, mutually contradicting; inconsistent.
      "Contradictory assertions." --South.
      [1913 Webster]

   2. Opposing or opposed; repugnant.
      [1913 Webster]

            Schemes . . . contradictory to common sense.
                                                  --Addisn.
      [1913 Webster]

WordNet (r) 3.0 (2006):

contradictory
    adj 1: of words or propositions so related that both cannot be
           true and both cannot be false; "`perfect' and `imperfect'
           are contradictory terms"
    2: that confounds or contradicts or confuses [syn:
       confounding, contradictory]
    3: in disagreement; "the figures are at odds with our findings";
       "contradictory attributes of unjust justice and loving
       vindictiveness"- John Morley [syn: at odds(p),
       conflicting, contradictory, self-contradictory]
    4: unable to be both true at the same time [syn:
       contradictory, mutually exclusive]
    n 1: two propositions are contradictories if both cannot be true
         (or both cannot be false) at the same time

Moby Thesaurus II by Grady Ward, 1.0:

164 Moby Thesaurus words for "contradictory":
   abjuratory, abnegative, absonant, adversary, adversative, adverse,
   adversive, alien, ambiguous, ambivalent, antagonistic, anti,
   antipathetic, antipodal, antipode, antipodean, antipole,
   antithesis, antithetic, antithetical, antonymous,
   at cross-purposes, at loggerheads, at odds, at variance, at war,
   balancing, breakaway, clashing, compensating, competitive, con,
   conflicting, confounding, confronting, confutative, confuting,
   contra, contradicting, contradistinct, contrapositive, contrarious,
   contrary, contrary to reason, contrasted, converse, counter,
   counteractant, counteracting, counteractive, counterbalancing,
   counterpoised, counterpole, countervailing, counterworking, cranky,
   cross, crotchety, dead against, denying, differing, disaccordant,
   disaffirming, disagreeable, disagreeing, disallowing, disavowing,
   disclaiming, discordant, discrepant, disharmonious, disowning,
   disproportionate, dissentient, dissident, dissonant, divergent,
   enemy, eyeball to eyeball, fallacious, faulty, flawed, fractious,
   grating, hostile, illogical, immiscible, inaccordant, inauthentic,
   incompatible, inconclusive, incongruous, inconsequent,
   inconsequential, inconsistent, inharmonious, inimical, invalid,
   inverse, irrational, jangling, jarring, loose, negating, negative,
   negatory, nonconformist, noncooperative, nonscientific,
   not following, nullifying, obstinate, obverse, opponent, opposed,
   opposing, opposite, oppositional, oppositive, oppugnant,
   out of accord, out of whack, overthwart, paradoxical, paralogical,
   perverse, polar, reactionary, reasonless, recalcitrant, recanting,
   refractory, refutative, refutatory, refuting, renitent,
   renunciative, renunciatory, repudiative, repugnant, resistant,
   reverse, revocative, revocatory, revolutionary, rival,
   self-annulling, self-contradictory, self-refuting, senseless,
   squared off, unauthentic, uncongenial, unconnected, uncooperative,
   unfavorable, unfriendly, unharmonious, unphilosophical,
   unpropitious, unreasonable, unscientific, variant,
   without reason