The Collaborative International Dictionary of English v.0.48:

no-show \no-show\ n.
   1. someone who shirks a duty.

   Syn: nonattender, truant.
        [WordNet 1.5]

   2. A person who is expected to attend a gathering but does
      not come. Specifically, a person who buys a ticket to a
      game or other entertainment and does not attend.
      [PJC]

WordNet (r) 3.0 (2006):

no-show
    n 1: a guest who fails to notify a hotel or restaurant when
         canceling a reservation
    2: someone who shirks duty [syn: no-show, nonattender,
       truant]