The Collaborative International Dictionary of English v.0.48:

Crusher \Crush"er\ (-?r), n.
   One who, or that which, crushes.
   [1913 Webster]

   Crusher gauge, an instrument for measuring the explosive
      force of gunpowder, etc., by its effect in compressing a
      piece of metal.
      [1913 Webster]

WordNet (r) 3.0 (2006):

crusher
    n 1: a device that crushes something

Moby Thesaurus II by Grady Ward, 1.0:

42 Moby Thesaurus words for "crusher":
   KO, cheese grater, clincher, comminutor, conclusive argument,
   death stroke, deathblow, end-all, ender, final stroke, finisher,
   finishing stroke, floorer, granulator, grater, grinder, kayo,
   kayo punch, knockdown argument, knockout, knockout blow, kominuter,
   last dab, levigator, masher, mill, millstone, mortar and pestle,
   nutmeg grater, pestle, pulverizer, quern, quernstone, quietus,
   rock crusher, roller, settler, shredder, sockdolager, steamroller,
   stopper, triturator