Source : Webster's Revised Unabridged Dictionary (1913)

Murder \Mur"der\, v. t. [imp. & p. p. {Murdered}; p. pr. & vb.
   n. {Murdering}.] [OE. mortheren, murtheren, AS. myr?rian;
   akin to OHG. murdiren, Goth. ma['u]r?rjan. See {Murder}, n.]
   1. To kill with premediated malice; to kill (a human being)
      willfully, deliberately, and unlawfully. See {Murder}, n.

   2. To destroy; to put an end to.

            [Canst thou] murder thy breath in middle of a word?
                                                  --Shak.

   3. To mutilate, spoil, or deform, as if with malice or
      cruelty; to mangle; as, to murder the king's English.

   Syn: To kill; assassinate; slay. See {Kill}.

Murder \Mur"der\, n. [OE. morder, morther, AS. mor[eth]or, fr.
   mor[eth] murder; akin to D. moord, OS. mor[eth], G., Dan., &
   Sw. mord, Icel. mor[eth], Goth. ma['u]r[thorn]r, OSlav.
   mr[=e]ti to die, Lith. mirti, W. marw dead, L. mors, mortis,
   death, mori, moriri, to die, Gr. broto`s (for mroto`s)
   mortal, 'a`mbrotos immortal, Skr. m[.r] to die, m[.r]ta
   death. [root]105. Cf. {Amaranth}, {Ambrosia}, {Mortal}.]
   The offense of killing a human being with malice prepense or
   aforethought, express or implied; intentional and unlawful
   homicide. ``Mordre will out.'' --Chaucer.

         The killing of their children had, in the account of
         God, the guilt of murder, as the offering them to idols
         had the guilt of idolatry.               --Locke.

         Slaughter grows murder when it goes too far. --Dryden.

   Note: Murder in the second degree, in most jurisdictions, is
         a malicious homicide committed without a specific
         intention to take life. --Wharton.

Source : WordNet®

murder
     v 1: kill intentionally and with premeditation; "The mafia boss
          ordered his enemies murdered" [syn: {slay}, {hit}, {dispatch},
           {bump off}, {polish off}, {remove}]
     2: alter so as to make unrecognizable; "The tourists murdered
        the French language" [syn: {mangle}, {mutilate}]

murder
     n : unlawful premeditated killing of a human being by a human
         being [syn: {slaying}, {execution}]