The Collaborative International Dictionary of English v.0.48:

Contradistinction \Con`tra*dis*tinc"tion\, n.
   Distinction by contrast.
   [1913 Webster]

         That there are such things as sins of infirmity in
         contradistinction to those of presumption is not to be
         questioned.                              --South.
   [1913 Webster]

WordNet (r) 3.0 (2006):

contradistinction
    n 1: a distinction drawn on the basis of contrast; "sculpture in
         contradistinction to painting"

Moby Thesaurus II by Grady Ward, 1.0:

44 Moby Thesaurus words for "contradistinction":
   antagonism, antipathy, antithesis, clashing, collision, con,
   conflict, confrontation, contradiction, contraindication,
   contraposition, contrariety, contrast, counterposition,
   cross-purposes, demarcation, differentiation, disagreement,
   discrepancy, distinction, distinctiveness, distinguishment,
   division, hairsplitting, hostility, inconsistency, inimicalness,
   microscopic distinction, nice distinction, nuance, oppositeness,
   opposition, opposure, oppugnance, oppugnancy, perversity, polarity,
   repugnance, segregation, separation, shade of difference, showdown,
   subtle distinction, trichoschistism