cleaver

from WordNet (r) 3.0 (2006)

cleaver
    n 1: a butcher's knife having a large square blade [syn:
         {cleaver}, {meat cleaver}, {chopper}]

from The Collaborative International Dictionary of English v.0.48

Cleaver \Cleav"er\, n.
   One who cleaves, or that which cleaves; especially, a
   butcher's instrument for cutting animal bodies into joints or
   pieces.
   [1913 Webster]