bumper
    n 1: a glass filled to the brim (especially as a toast); "we
         quaffed a bumper of ale"
    2: a mechanical device consisting of bars at either end of a
       vehicle to absorb shock and prevent serious damage

Bumper \Bum"per\, n. [A corruption of bumbard, bombard, a large
   drinking vessel.]
   1. A cup or glass filled to the brim, or till the liquor runs
      over, particularly in drinking a health or toast.
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            He frothed his bumpers to the brim.   --Tennyson.
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   2. A covered house at a theater, etc., in honor of some
      favorite performer. [Cant]
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Bumper \Bump"er\, n.
   1. That which bumps or causes a bump.
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   2. Anything which resists or deadens a bump or shock, such as
      a metal or rubber rim extending from an object; a buffer.
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   3. Specifically: (Motor vehicles) A protective guard device,
      usually of metal or rubber, attached horizontally to the
      front or rear of the frame of a vehicle, designed to
      resist or deaden a bump or shock, and to prevent damage to
      the main frame of the vehicle in low-velocity collisions.
      [PJC]