The Collaborative International Dictionary of English v.0.48:

Equality \E*qual"i*ty\, n.; pl. Equalities. [L. aequalitas,
   fr. aequalis equal. See Equal.]
   1. The condition or quality of being equal; agreement in
      quantity or degree as compared; likeness in bulk, value,
      rank, properties, etc.; as, the equality of two bodies in
      length or thickness; an equality of rights.
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            A footing of equality with nobles.    --Macaulay.
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   2. Sameness in state or continued course; evenness;
      uniformity; as, an equality of temper or constitution.
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   3. Evenness; uniformity; as, an equality of surface.
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   4. (Math.) Exact agreement between two expressions or
      magnitudes with respect to quantity; -- denoted by the
      symbol =; thus, a = x signifies that a contains the same
      number and kind of units of measure that x does.
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   Confessional equality. See under Confessional.
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WordNet (r) 3.0 (2006):

equality
    n 1: the quality of being the same in quantity or measure or
         value or status [ant: inequality]
    2: a state of being essentially equal or equivalent; equally
       balanced; "on a par with the best" [syn: equality,
       equivalence, equation, par]