The Collaborative International Dictionary of English v.0.48:

Laugher \Laugh"er\, n.
   1. One who laughs.
      [1913 Webster]

   2. A variety of the domestic pigeon.
      [1913 Webster]

   3. A contest in which one side wins easily; a lopsided
      victory. [Informal]
      [PJC]

   4. A blatantly false statement, especially a self-serving
      one. [Slang]
      [PJC]

WordNet (r) 3.0 (2006):

laugher
    n 1: a person who is laughing or who laughs easily
    2: an easy victory [syn: runaway, blowout, romp,
       laugher, shoo-in, walkaway]