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1.                 From The Collaborative International Dictionary of English v.0.48:
                   
   
   
                   
                     
   Sapper \Sap"per\, n. [Cf. F. sapeur.]
      One who saps; specifically (Mil.), one who is employed in
      working at saps, building and repairing fortifications, and
      the like.
      [1913 Webster]