The Collaborative International Dictionary of English v.0.48:

Disappoint \Dis`ap*point"\, v. t. [imp. & p. p. Disapointed;
   p. pr. & vb. n. Disappointing.] [OF. desapointier, F.
   d['e]sappointer; pref. des- (L. dis-) + apointier, F.
   appointier, to appoint. See Appoint.]
   1. To defeat of expectation or hope; to hinder from the
      attainment of that which was expected, hoped, or desired;
      to balk; as, a man is disappointed of his hopes or
      expectations, or his hopes, desires, intentions,
      expectations, or plans are disappointed; a bad season
      disappoints the farmer of his crops; a defeat disappoints
      an enemy of his spoil.
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            I was disappointed, but very agreeably. --Macaulay.
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   Note: Disappointed of a thing not obtained; disappointed in a
         thing obtained.
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   2. To frustrate; to fail; to hinder of result.
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            His retiring foe
            Shrinks from the wound, and disappoints the blow.
                                                  --Addison.

   Syn: To tantalize; fail; frustrate; balk; baffle; delude;
        foil; defeat. See Tantalize.
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