Source : Webster's Revised Unabridged Dictionary (1913)

Malicious \Ma*li"cious\, a. [Of. malicius, F. malicieux, fr. L.
   malitiosus. See {Malice}.]
   1. Indulging or exercising malice; harboring ill will or
      enmity.

            I grant him bloody, . . . Sudden, malicious,
            smacking of every sin That has a name. --Shak.

   2. Proceeding from hatred or ill will; dictated by malice;
      as, a malicious report; malicious mischief.

   3. (Law)With wicked or mischievous intentions or motives;
      wrongful and done intentionally without just cause or
      excuse; as, a malicious act.

   {Malicious abandonment}, the desertion of a wife or husband
      without just cause. --Burrill.

   {Malicious mischief} (Law), malicious injury to the property
      of another; -- an offense at common law. --Wharton.

   {Malicious prosecution} or {arrest} (Law), a wanton
      prosecution or arrest, by regular process in a civil or
      criminal proceeding, without probable cause. --Bouvier.

   Syn: Ill-disposed; evil-minded; mischievous; envious;
        malevolent; invidious; spiteful; bitter; malignant;
        rancorous; malign. -- {Ma*li"cious*ly}, adv. --
        {Ma*li"cious*ness}, n.

Source : WordNet®

maliciousness
     n : feeling a need to see others suffer [syn: {malice}, {spite},
          {spitefulness}, {venom}]