The Collaborative International Dictionary of English v.0.48:

Disparity \Dis*par"i*ty\, n.; pl. Disparities. [LL.
   disparitas, fr. L. dispar unlike, unequal; dis- + par equal:
   cf. F. disparit['e]. See Par, Peer.]
   Inequality; difference in age, rank, condition, or
   excellence; dissimilitude; -- followed by between, in, of, as
   to, etc.; as, disparity in, or of, years; a disparity as to
   color.
   [1913 Webster]

         The disparity between God and his intelligent
         creatures.                               --I. Taylor.
   [1913 Webster]

         The disparity of numbers was not such as ought to cause
         any uneasiness.                          --Macaulay.

   Syn: Inequality; unlikeness; dissimilitude; disproportion;
        difference.
        [1913 Webster]

WordNet (r) 3.0 (2006):

disparity
    n 1: inequality or difference in some respect

Moby Thesaurus II by Grady Ward, 1.0:

124 Moby Thesaurus words for "disparity":
   agreement to disagree, alienation, antagonism, apostasy,
   argumentation, asymmetry, bad copy, bad likeness, camouflage,
   clashing, conflict, contradiction, contrariety, contrast,
   controversy, counter-culture, cross-purposes, departure, deviation,
   difference, difference of opinion, difficulty, disaccord,
   disaccordance, disagreement, disapprobation, disapproval,
   disconformity, discongruity, discord, discordance, discordancy,
   discrepancy, discreteness, disequilibrium, disguise, disharmony,
   disproportion, dissatisfaction, dissemblance, dissension, dissent,
   dissentience, dissidence, dissimilarity, dissimilation,
   dissimilitude, dissonance, distinction, distinctness, disunion,
   disunity, divergence, divergency, diversity, dividedness, division,
   dropping out, faction, far cry, gap, heterogeneity, imbalance,
   imparity, inaccordance, inadequacy, incommensurability,
   incomparability, incompatibility, incongruity, inconsistency,
   inconsonance, inequality, inequity, inharmoniousness, inharmony,
   injustice, insufficiency, irreconcilability, irregularity, jarring,
   makeup, mere caricature, minority opinion, misunderstanding,
   mixture, negation, nonagreement, nonassent, nonconcurrence,
   nonconformity, nonconsent, nonuniformity, odds, opposition,
   oppugnancy, otherness, overbalance, polarization, poor imitation,
   recusance, recusancy, rejection, repudiation, repugnance,
   secession, separateness, shortcoming, unbalance, unconformity,
   underground, unevenness, unfair discrimination, unharmoniousness,
   unlikeness, unorthodoxy, unresemblance, unsameness, unsimilarity,
   variance, variation, variegation, variety, withdrawal