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]