The Collaborative International Dictionary of English v.0.48:

Discrimination \Dis*crim`i*na"tion\, n. [L. discriminatio the
   contrasting of opposite thoughts.]
   1. The act of discriminating, distinguishing, or noting and
      marking differences.
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            To make an anxious discrimination between the
            miracle absolute and providential.    --Trench.
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   2. The state of being discriminated, distinguished, or set
      apart. --Sir J. Reynolds.
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   3. (Railroads) The arbitrary imposition of unequal tariffs
      for substantially the same service.
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            A difference in rates, not based upon any
            corresponding difference in cost, constitutes a case
            of discrimination.                    --A. T.
                                                  Hadley.
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   4. The quality of being discriminating; faculty of nicely
      distinguishing; acute discernment; as, to show great
      discrimination in the choice of means.
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   5. That which discriminates; mark of distinction.

   Syn: Discernment; penetration; clearness; acuteness;
        judgment; distinction. See Discernment.
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WordNet (r) 3.0 (2006):

discrimination
    n 1: unfair treatment of a person or group on the basis of
         prejudice [syn: discrimination, favoritism,
         favouritism]
    2: the cognitive process whereby two or more stimuli are
       distinguished [syn: discrimination, secernment]