The Collaborative International Dictionary of English v.0.48:

Inequity \In*eq"ui*ty\, n.
   Lack of equity; injustice; wrong. "Some form of inequity."
   --H. Spencer. Inequivalve

Moby Thesaurus II by Grady Ward, 1.0:

34 Moby Thesaurus words for "inequity":
   asymmetry, contrariety, difference, disequilibrium, disparity,
   disproportion, heterogeneity, illegality, imbalance, improperness,
   impropriety, inadequacy, inequality, inequitableness,
   iniquitousness, iniquity, injustice, insufficiency, irregularity,
   nonuniformity, odds, overbalance, shortcoming, unbalance,
   undueness, unevenness, unfair discrimination, unfairness,
   unjustness, unlawfulness, unmeetness, wrong, wrongfulness,
   wrongness