WordNet (r) 3.0 (2006):

nonuniformity
    n 1: the quality of being diverse and interesting [ant:
         uniformity, uniformness]

Moby Thesaurus II by Grady Ward, 1.0:

167 Moby Thesaurus words for "nonuniformity":
   Proteus, adaptability, adjustability, allotropism, allotropy,
   alterability, arrhythmia, asperity, asymmetry, bad copy,
   bad likeness, broken thread, brokenness, bumpiness, camouflage,
   capriciousness, changeability, changeableness, changefulness,
   choppiness, contrariety, contrast, cragginess, derangement,
   desultoriness, difference, disarrangement, disarray,
   disarticulation, discomfiture, discomposure, disconcertedness,
   disconnectedness, disconnection, discontinuance, discontinuation,
   discontinuity, discontinuousness, discreteness, disequilibrium,
   disguise, disharmony, dishevelment, disintegration, disjunction,
   disorder, disorderliness, disorganization, disparity,
   disproportion, disruption, dissemblance, dissimilarity,
   dissimilation, dissimilitude, disturbance, divergence,
   diversification, diversity, eccentricity, entropy, episode,
   erraticness, fibrillation, fitfulness, fits and starts,
   flexibility, fluctuation, fluidity, granulation, haphazardness,
   harshness, her infinite variety, heterogeneity, heteromorphism,
   hispidity, imbalance, impermanence, inadequacy, incoherence,
   incommensurability, incomparability, incompleteness, inconstancy,
   indiscriminateness, inequality, inequity, inharmonious harmony,
   injustice, insufficiency, intermittence, irregularity, jaggedness,
   jerkiness, joltiness, makeup, malleability, manifoldness,
   mere caricature, mobility, modifiability, most admired disorder,
   movability, multifariousness, multiplicity, mutability,
   non sequitur, noncontinuance, nonlinearity, nonseriality,
   nonsymmetry, odds, omnifariousness, omniformity, overbalance,
   parenthesis, patchiness, permutability, perturbation, plasticity,
   polymorphism, poor imitation, promiscuity, promiscuousness,
   raggedness, randomness, resilience, rough air, roughness,
   rubberiness, ruggedness, rugosity, scraggliness, shapeshifter,
   shortcoming, spasticity, sporadicity, sporadicness, spottiness,
   stagger, suppleness, tooth, transience, transitoriness, turbulence,
   unbalance, uncertainty, unevenness, unfair discrimination,
   unlikeness, unmethodicalness, unpredictability, unresemblance,
   unsameness, unsimilarity, unsmoothness, unsteadiness, unsymmetry,
   unsystematicness, ununiformity, upset, variability, variation,
   variegation, variety, whimsicality, wobble