The Collaborative International Dictionary of English v.0.48:

Repugnance \Re*pug"nance\ (-nans), Repugnancy \Re*pug"nan*cy\
   (-nan-s?), n. [F. r['e]pugnance, L. repugnantia.]
   The state or condition of being repugnant; opposition;
   contrariety; especially, a strong instinctive antagonism;
   aversion; reluctance; unwillingness, as of mind, passions,
   principles, qualities, and the like.
   [1913 Webster]

         That which causes us to lose most of our time is the
         repugnance which we naturally have to labor. --Dryden.
   [1913 Webster]

         Let the foes quietly cut their throats,
         Without repugnancy.                      --Shak.
   [1913 Webster]

   Syn: Aversion; reluctance; unwillingness; dislike; antipathy;
        hatred; hostility; irreconcilableness; contrariety;
        inconsistency. See Dislike.
        [1913 Webster]

WordNet (r) 3.0 (2006):

repugnance
    n 1: intense aversion [syn: repugnance, repulsion,
         revulsion, horror]
    2: the relation between propositions that cannot both be true at
       the same time [syn: incompatibility, mutual
       exclusiveness, inconsistency, repugnance]

Moby Thesaurus II by Grady Ward, 1.0:

199 Moby Thesaurus words for "repugnance":
   Anglophobia, Russophobia, abhorrence, abominability, abomination,
   allergy, antagonism, anti-Semitism, antipathy, antithesis,
   argumentation, averseness, aversion, backlash, backwardness,
   bad blood, baseness, beastliness, belligerence, bigotry, clash,
   clashing, cold sweat, collision, competition, conflict,
   confrontation, confutation, contemptibility, contention,
   contradiction, contradistinction, contraindication, contraposition,
   contrariety, contrariness, contrast, controversy, counteraction,
   counterposition, counterworking, crankiness, creeping flesh,
   cross-purposes, crotchetiness, crudeness, cursoriness,
   despicability, despicableness, despitefulness, detestation,
   difference, disaccord, disaccordance, disagreement, discord,
   discordance, discordancy, discrepancy, disgust, disgustingness,
   disharmony, disinclination, dislike, disobedience, disparity,
   disrelish, dissension, dissent, dissidence, dissonance, distaste,
   disunion, disunity, divergence, diversity, emetic, enmity,
   execration, faction, fetidness, foot-dragging, foulness,
   fractiousness, friction, fulsomeness, grossness, grudging consent,
   grudgingness, harshness, hate, hatefulness, hatred, heinousness,
   horror, hostility, ignobility, inaccordance, inconsistency,
   indisposedness, indisposition, indocility, inequality,
   inimicalness, interference, intractableness, jarring, kick,
   lack of enthusiasm, lack of zeal, loathing, loathsomeness,
   malevolence, malice, malignity, misandry, misanthropy, misogyny,
   mortal horror, mutinousness, nastiness, nausea, nauseant,
   nauseousness, negation, negativeness, noisomeness, nolition,
   nonconformity, noncooperation, noxiousness, objectionability,
   objectionableness, obnoxiousness, obscenity, obstinacy, odiousness,
   odium, offensiveness, oppositeness, opposition, opposure,
   oppugnance, oppugnancy, overripeness, perfunctoriness,
   perverseness, perversity, polarity, putridity, putridness,
   quarrelsomeness, race hatred, racism, rancidity, rancidness,
   rankness, reaction, rebarbativeness, recalcitrance, recalcitrancy,
   recoil, refractoriness, refusal, reluctance, renitence, renitency,
   repellence, repellency, repercussion, repulsion, repulsiveness,
   resistance, revolt, rivalry, rottenness, showdown, shuddering,
   sickener, slowness, spite, spitefulness, stubbornness, sulk,
   sulkiness, sulks, sullenness, swimming upstream, uncooperativeness,
   unenthusiasm, unharmoniousness, unspeakableness, unwillingness,
   variance, vials of hate, vials of wrath, vileness, vying,
   xenophobia