Source : Webster's Revised Unabridged Dictionary (1913)

Criminal \Crim"i*nal\, n.
   One who has commited a crime; especially, one who is found
   guilty by verdict, confession, or proof; a malefactor; a
   felon.

Criminal \Crim"i*nal\ (kr?m"?-nal), a. [L. criminalis, fr.
   crimen: cf. F. criminel. See {Crime}.]
   1. Guilty of crime or sin.

            The neglect of any of the relative duties renders us
            criminal in the sight of God.         --Rogers.

   2. Involving a crime; of the nature of a crime; -- said of an
      act or of conduct; as, criminal carelessness.

            Foppish and fantastic ornaments are only indications
            of vice, not criminal in themselves.  --Addison.

   3. Relating to crime; -- opposed to civil; as, the criminal
      code.

            The officers and servants of the crown, violating
            the personal liberty, or other right of the subject
            . . . were in some cases liable to criminal process.
                                                  --Hallam.

   {Criminal action} (Law), an action or suit instituted to
      secure conviction and punishment for a crime.

   {Criminal conversation} (Law), unlawful intercourse with a
      married woman; adultery; -- usually abbreviated, crim.
      con.

   {Criminal law}, the law which relates to crimes.

Source : WordNet®

criminal
     adj 1: relating to crime or its punishment; "criminal court"
     2: bringing or deserving severe rebuke or censure; "a criminal
        waste of talent"; "a deplorable act of violence";
        "adultery is as reprehensible for a husband as for a wife"
        [syn: {condemnable}, {deplorable}, {reprehensible}]
     3: guilty of crime or serious offense; "criminal in the sight
        of God and man"
     4: involving or being or having the nature of a crime; "a
        criminal offense"; "criminal abuse"; "felonious intent"
        [syn: {felonious}]

criminal
     n : someone who has committed (or been legally convicted of) a
         crime [syn: {felon}, {crook}, {outlaw}, {malefactor}]