The Collaborative International Dictionary of English v.0.48:

Ashamed \A*shamed"\, a. [Orig. a p. p. of ashame, v. t.]
   Affected by shame; abashed or confused by guilt, or a
   conviction or consciousness of some wrong action or
   impropriety. "I am ashamed to beg." --Wyclif.
   [1913 Webster]

         All that forsake thee shall be ashamed.  --Jer. xvii.
                                                  13.
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         I began to be ashamed of sitting idle.   --Johnson.
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         Enough to make us ashamed of our species. --Macaulay.
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         An ashamed person can hardly endure to meet the gaze of
         those present.                           --Darwin.
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   Note: Ashamed seldom precedes the noun or pronoun it
         qualifies. By a Hebraism, it is sometimes used in the
         Bible to mean disappointed, or defeated.
         [1913 Webster]

WordNet (r) 3.0 (2006):

ashamed
    adj 1: feeling shame or guilt or embarrassment or remorse; "are
           you ashamed for having lied?"; "felt ashamed of my torn
           coat" [ant: unashamed]