Source : Webster's Revised Unabridged Dictionary (1913)

Trapper \Trap"per\, n. [From {Trap} to insnare.]
   1. One who traps animals; one who makes a business of
      trapping animals for their furs. --W. Irving.

   2. (Mining) A boy who opens and shuts a trapdoor in a gallery
      or level. --Raymond.

Source : WordNet®

trapper
     n : someone who sets traps for animals (usually to obtain their
         furs)