trapper n 1: someone who sets traps for animals (usually to obtain their furs)
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. [1913 Webster] 2. (Mining) A boy who opens and shuts a trapdoor in a gallery or level. --Raymond. [1913 Webster]