The Collaborative International Dictionary of English v.0.48:

Repugnant \Re*pug"nant\ (-nant), a. [F. r['e]pugnant, or L.
   repugnans, -antis, p. pr. of repugnare. See Repugn.]
   Disposed to fight against; hostile; at war with; being at
   variance; contrary; inconsistent; refractory; disobedient;
   also, distasteful in a high degree; offensive; -- usually
   followed by to, rarely and less properly by with; as, all
   rudeness was repugnant to her nature.
   [1913 Webster]

         [His sword] repugnant to command.        --Shak.
   [1913 Webster]

         There is no breach of a divine law but is more or less
         repugnant unto the will of the Lawgiver, God himself.
                                                  --Perkins.
   [1913 Webster]

   Syn: Opposite; opposed; adverse; contrary; inconsistent;
        irreconcilable; hostile; inimical.
        [1913 Webster]

WordNet (r) 3.0 (2006):

repugnant
    adj 1: offensive to the mind; "an abhorrent deed"; "the obscene
           massacre at Wounded Knee"; "morally repugnant customs";
           "repulsive behavior"; "the most repulsive character in
           recent novels" [syn: abhorrent, detestable,
           obscene, repugnant, repulsive]

Moby Thesaurus II by Grady Ward, 1.0:

201 Moby Thesaurus words for "repugnant":
   abhorrent, abjuratory, abnegative, abominable, acrid, adversary,
   adversative, adverse, adversive, alien, antagonistic, anti,
   antipathetic, antithetic, antonymous, at cross-purposes,
   at loggerheads, at odds, at variance, at war, awful, balancing,
   base, beastly, belligerent, below contempt, beneath contempt,
   bitter, breakaway, caustic, clashing, colliding, compensating,
   competitive, con, conflicting, confronting, contemptible,
   contradicting, contradictory, contradistinct, contrapositive,
   contrarious, contrary, contrasted, converse, counter,
   counteractant, counteracting, counteractive, counterbalancing,
   counterpoised, countervailing, counterworking, cranky, cross,
   crotchety, crude, dead against, denying, despicable, despiteful,
   detestable, differing, disaccordant, disaffirming, disagreeable,
   disagreeing, disallowing, disavowing, disclaiming, discordant,
   discrepant, disgusting, disharmonious, disowning, disproportionate,
   dissentient, dissident, dissonant, distasteful, divergent,
   dreadful, enemy, execrable, extraneous, extrinsic,
   eyeball to eyeball, fetid, forbidding, foreign, foul, fractious,
   frightful, full of hate, fulsome, ghastly, grating, grisly, gross,
   gruesome, hateful, heinous, hideous, horrible, horrid, hostile,
   ignoble, immiscible, inaccordant, incompatible, incongruous,
   inconsistent, inconsonant, inharmonious, inimical, intolerable,
   inverse, invidious, jangling, jarring, loathsome, malevolent,
   malicious, malignant, malodorous, mephitic, miasmal, miasmic,
   nasty, nauseating, nauseous, negative, negatory, noisome,
   nonconformist, noncooperative, noxious, objectionable, obnoxious,
   obscene, obstinate, obverse, odious, offensive, opponent, opposed,
   opposing, opposite, oppositional, oppositive, oppugnant,
   out of accord, out of whack, overthwart, perverse, quarrelsome,
   rancorous, reactionary, rebarbative, recalcitrant, recanting,
   refractory, renitent, renunciative, renunciatory, repellent,
   repelling, repudiative, repulsive, resistant, reverse, revocative,
   revocatory, revolting, revolutionary, revulsive, rival,
   set against, sickening, sore, spiteful, squared off, stinking,
   terrible, uncongenial, uncooperative, unfavorable, unfriendly,
   ungenial, unharmonious, unpalatable, unpleasant, unpropitious,
   unsavory, unsympathetic, variant, venomous, vile, virulent,
   vitriolic



Bouvier's Law Dictionary, Revised 6th Ed (1856):

REPUGNANT. That which is contrary to something else; a repugnant condition
is one contrary to the contract itself; as, if I grant you a house and lot
in fee, upon condition that you shall not aliens, the condition is repugnant
and void. Bac. Ab. Conditions, L.