Source : Webster's Revised Unabridged Dictionary (1913)

Libertine \Lib"er*tine\ (-t[i^]n), n. [L. libertinus freedman,
   from libertus one made free, fr. liber free: cf. F. libertin.
   See {Liberal}.]
   1. (Rom. Antiq.) A manumitted slave; a freedman; also, the
      son of a freedman.

   2. (Eccl. Hist.) One of a sect of Anabaptists, in the
      fifteenth and early part of the sixteenth century, who
      rejected many of the customs and decencies of life, and
      advocated a community of goods and of women.

   3. One free from restraint; one who acts according to his
      impulses and desires; now, specifically, one who gives
      rein to lust; a rake; a debauchee.

            Like a puffed and reckless libertine, Himself the
            primrose path of dalliance treads.    --Shak.

   4. A defamatory name for a freethinker. [Obsoles.]

Libertine \Lib"er*tine\, a. [L. libertinus of a freedman: cf. F.
   libertin. See {Libertine}, n. ]
   1. Free from restraint; uncontrolled. [Obs.]

            You are too much libertine.           --Beau. & Fl.

   2. Dissolute; licentious; profligate; loose in morals; as,
      libertine principles or manners. --Bacon.

Source : WordNet®

libertine
     adj : unrestrained by convention or morality; "Congreve draws a
           debauched aristocratic society"; "deplorably dissipated
           and degraded"; "riotous living"; "fast women" [syn: {debauched},
            {degenerate}, {degraded}, {dissipated}, {dissolute}, {profligate},
            {riotous}, {fast}]
     n : a dissolute person; usually a man who is morally
         unrestrained [syn: {debauchee}, {rounder}]