'Murderer' definitions:

Definition of 'murderer'

From: WordNet
noun
A criminal who commits homicide (who performs the unlawful premeditated killing of another human being) [syn: murderer, liquidator, manslayer]

Definition of 'Murderer'

From: GCIDE
  • Murderer \Mur"der*er\ (m[^u]r"d[~e]r*[~e]r), n.
  • 1. One guilty of murder; a person who, in possession of his reason, unlawfully kills a human being with premeditated malice. [1913 Webster]
  • 2. A small cannon, formerly used for clearing a ship's decks of boarders; -- called also murdering piece. [Obs.] [1913 Webster]