Source : Webster's Revised Unabridged Dictionary (1913)

Villain \Vil"lain\, a. [F. vilain.]
   Villainous. [R.] --Shak.

Villain \Vil"lain\, v. t.
   To debase; to degrade. [Obs.] --Sir T. More.

Villain \Vil"lain\, n. [OE. vilein, F. vilain, LL. villanus,
   from villa a village, L. villa a farm. See {Villa}.]
   1. (Feudal Law) One who holds lands by a base, or servile,
      tenure, or in villenage; a feudal tenant of the lowest
      class, a bondman or servant. [In this sense written also
      {villan}, and {villein}.]

            If any of my ansectors was a tenant, and a servant,
            and held his lands as a villain to his lord, his
            posterity also must do so, though accidentally they
            become noble.                         --Jer. Taylor.

   Note: Villains were of two sorts; villains regardant, that
         is, annexed to the manor (LL. adscripti gleb[ae]); and
         villains in gross, that is, annexed to the person of
         their lord, and transferable from one to another.
         --Blackstone.

   2. A baseborn or clownish person; a boor. [R.]

            Pour the blood of the villain in one basin, and the
            blood of the gentleman in another, what difference
            shall there be proved?                --Becon.

   3. A vile, wicked person; a man extremely depraved, and
      capable or guilty of great crimes; a deliberate scoundrel;
      a knave; a rascal; a scamp.

            Like a villain with a smiling cheek.  --Shak.

            Calm, thinking villains, whom no faith could fix.
                                                  --Pope.

Source : WordNet®

villain
     n 1: a wicked or evil person; someone who does evil deliberately
          [syn: {scoundrel}]
     2: the principle bad character in a film or work of fiction
        [syn: {baddie}]