Murderer /(mûr"dẽr*ẽr)/

Mur·der·er

Murderer

n.
  1. One guilty of murder; a person who, in possession of his reason, unlawfully kills a human being with premeditated malice.
  2. A small cannon, formerly used for clearing a ship's decks of boarders; -- called also murdering piece. [Obs.]