Source : Webster's Revised Unabridged Dictionary (1913)

Malice \Mal"ice\, n. [F. malice, fr. L. malitia, from malus bad,
   ill, evil, prob. orig., dirty, black; cf. Gr. ? black, Skr.
   mala dirt. Cf. {Mauger}.]
   1. Enmity of heart; malevolence; ill will; a spirit
      delighting in harm or misfortune to another; a disposition
      to injure another; a malignant design of evil. ``Nor set
      down aught in malice.'' --Shak.

            Envy, hatred, and malice are three distinct passions
            of the mind.                          --Ld. Holt.

   2. (Law) Any wicked or mischievous intention of the mind; a
      depraved inclination to mischief; an intention to vex,
      annoy, or injure another person, or to do a wrongful act
      without just cause or cause or excuse; a wanton disregard
      of the rights or safety of others; willfulness.

   {Malice aforethought} or {prepense}, malice previously and
      deliberately entertained.

   Syn: Spite; ill will; malevolence; grudge; pique; bitterness;
        animosity; malignity; maliciousness; rancor; virulence.

   Usage: See {Spite}. -- {Malevolence}, {Malignity},
          {Malignancy}. Malice is a stronger word than
          malevolence, which may imply only a desire that evil
          may befall another, while malice desires, and perhaps
          intends, to bring it about. Malignity is intense and
          deepseated malice. It implies a natural delight in
          hating and wronging others. One who is malignant must
          be both malevolent and malicious; but a man may be
          malicious without being malignant.

                Proud tyrants who maliciously destroy And ride
                o'er ruins with malignant joy.    --Somerville.

                in some connections, malignity seems rather more
                pertinently applied to a radical depravity of
                nature, and malignancy to indications of this
                depravity, in temper and conduct in particular
                instances.                        --Cogan.

Source : WordNet®

malice aforethought
     n : (law) criminal intent; the thoughts and intentions behind a
         wrongful act (including knowledge that the act is
         illegal); often at issue in murder trials [syn: {mens rea}]