The Collaborative International Dictionary of English v.0.48:

Entertainment \En`ter*tain"ment\, n. [Cf. OF. entretenement.]
   1. The act of receiving as host, or of amusing, admitting, or
      cherishing; hospitable reception; also, reception or
      treatment, in general.
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            The entertainment of Christ by faith. --Baxter.
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            The sincere entertainment and practice of the
            precepts of the gospel.               --Bp. Sprat.
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   2. That which entertains, or with which one is entertained;
      as:
      (a) Hospitality; hospitable provision for the wants of a
          guest; especially, provision for the table; a
          hospitable repast; a feast; a formal or elegant meal.
      (b) That which engages the attention agreeably, amuses or
          diverts, whether in private, as by conversation, etc.,
          or in public, by performances of some kind; amusement.
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                Theatrical entertainments conducted with greater
                elegance and refinement.          --Prescott.
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   3. Admission into service; service.
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            Some band of strangers in the adversary's
            entertainment.                        --Shak.
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   4. Payment of soldiers or servants; wages. [Obs.]
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            The entertainment of the general upon his first
            arrival was but six shillings and eight pence. --Sir
                                                  J. Davies.

   Syn: Amusement; diversion; recreation; pastime; sport; feast;
        banquet; repast; carousal.
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WordNet (r) 3.0 (2006):

entertainment
    n 1: an activity that is diverting and that holds the attention
         [syn: entertainment, amusement]

The Devil's Dictionary (1881-1906):

ENTERTAINMENT, n.  Any kind of amusement whose inroads stop short of
death by injection.