The Collaborative International Dictionary of English v.0.48:

Uneven \Un*e"ven\, a. [AS. unefen. See Un- not, and Even,
   a.]
   1. Not even; not level; not uniform; rough; as, an uneven
      road or way; uneven ground.
      [1913 Webster]

   2. Not equal; not of equal length.
      [1913 Webster]

            Hebrew verse consists of uneven feet. --Peacham.
      [1913 Webster]

   3. Not divisible by two without a remainder; odd; -- said of
      numbers; as, 3, 7, and 11 are uneven numbers.
      [1913 Webster] Un*e"ven*ly, adv. -- Un*e"ven*ness, n.
      [1913 Webster]

WordNet (r) 3.0 (2006):

unevenness
    n 1: the quality of being uneven and lacking uniformity [syn:
         unevenness, variability] [ant: evenness,
         invariability]
    2: the quality of being unbalanced [ant: evenness]

Moby Thesaurus II by Grady Ward, 1.0:

120 Moby Thesaurus words for "unevenness":
   adulteration, arrhythmia, asperity, asymmetry, brokenness,
   bumpiness, capriciousness, changeability, changeableness,
   choppiness, contrariety, cragginess, dappleness, defectibility,
   defectiveness, deficiency, desultoriness, deviation, difference,
   differentiation, disconnectedness, discontinuity, disequilibrium,
   disorder, disparity, disproportion, divarication, divergence,
   diversification, eccentricity, erraticness, erroneousness,
   fallibility, faultiness, fibrillation, fitfulness, fits and starts,
   fluctuation, granulation, harshness, heterogeneity, hispidity,
   imbalance, immaturity, impairment, imparity, imperfection,
   impurity, inaccuracy, inadequacy, inadequateness, incompleteness,
   inconsistency, inconstancy, inequality, inequity, inexactitude,
   inexactness, injustice, instability, insufficiency, intermittence,
   irregularity, jaggedness, jerkiness, joltiness, lack, mediocrity,
   mercuriality, motleyness, mutability, nonconformism, nonconformity,
   nonstandardization, nonuniformity, odds, overbalance, patchiness,
   pluralism, raggedness, rough air, roughness, ruggedness, rugosity,
   scraggliness, shortage, shortcoming, sketchiness, spasticity,
   sporadicity, sporadicness, spottiness, stagger, tooth, turbulence,
   unbalance, uncertainty, unconformism, unconformity, undevelopment,
   unfair discrimination, unmethodicalness, unorthodoxy,
   unperfectedness, unpredictability, unsmoothness, unsoundness,
   unsteadiness, unsystematicness, ununiformity, variability,
   variation, variegation, variety, variousness, versatility, want,
   wavering, whimsicality, wobble