The Collaborative International Dictionary of English v.0.48:

Contempt \Con*tempt"\ (k[o^]n*t[e^]mt"; 215), n. [L. contemptus,
   fr. contemnere: cf. OF. contempt. See Contemn.]
   1. The act of contemning or despising; the feeling with which
      one regards that which is esteemed mean, vile, or
      worthless; disdain; scorn.
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            Criminal contempt of public feeling.  --Macaulay.
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            Nothing, says Longinus, can be great, the contempt
            of which is great.                    --Addison.
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   2. The state of being despised; disgrace; shame.
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            Contempt and begarry hangs upon thy back. --Shak.
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   3. An act or expression denoting contempt.
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            Little insults and contempts.         --Spectator.
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            The contempt and anger of his lip.    --Shak.
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   4. (Law) Disobedience of the rules, orders, or process of a
      court of justice, or of rules or orders of a legislative
      body; disorderly, contemptuous, or insolent language or
      behavior in presence of a court, tending to disturb its
      proceedings, or impair the respect due to its authority.
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   Note: Contempt is in some jurisdictions extended so as to
         include publications reflecting injuriously on a court
         of justice, or commenting unfairly on pending
         proceedings; in other jurisdictions the courts are
         prohibited by statute or by the constitution from thus
         exercising this process.

   Syn: Disdain; scorn; derision; mockery; contumely; neglect;
        disregard; slight.
        [1913 Webster]

WordNet (r) 3.0 (2006):

contempt
    n 1: lack of respect accompanied by a feeling of intense
         dislike; "he was held in contempt"; "the despite in which
         outsiders were held is legendary" [syn: contempt,
         disdain, scorn, despite]
    2: a manner that is generally disrespectful and contemptuous
       [syn: contempt, disrespect]
    3: open disrespect for a person or thing [syn: contempt,
       scorn]
    4: a willful disobedience to or disrespect for the authority of
       a court or legislative body

The Devil's Dictionary (1881-1906):

CONTEMPT, n.  The feeling of a prudent man for an enemy who is too
formidable safely to be opposed.