stabber

from WordNet (r) 3.0 (2006)

stabber
    n 1: someone who stabs another person

from The Collaborative International Dictionary of English v.0.48

Stabber \Stab"ber\ (st[a^]b"b[~e]r), n.
   1. One who, or that which, stabs; a privy murderer.
      [1913 Webster]

   2. (Naut.) A small marline spike; a pricker.
      [1913 Webster]