Source : Webster's Revised Unabridged Dictionary (1913)

Roulette \Rou*lette"\, n. [F., properly, a little wheel or ball.
   See {Rouleau}, {Roll}.]
   1. A game of chance, in which a small ball is made to move
      round rapidly on a circle divided off into numbered red
      and black spaces, the one on which it stops indicating the
      result of a variety of wagers permitted by the game.

   2. (Fine Arts)
      (a) A small toothed wheel used by engravers to roll over a
          plate in order to order to produce rows of dots.
      (b) A similar wheel used to roughen the surface of a
          plate, as in making alterations in a mezzotint.

   3. (Geom.) the curve traced by any point in the plane of a
      given curve when the latter rolls, without sliding, over
      another fixed curve. See {Cycloid}, and {Epycycloid}.

Roulette \Rou*lette"\, n.
   A small toothed wheel used to make short incisions in paper,
   as a sheet of postage stamps to facilitate their separation.

Roulette \Rou*lette"\, v. t.
   To make short incisions in with a roulette; to separate by
   incisions made with a roulette; as, to roulette a sheet of
   postage stamps.

Source : WordNet®

roulette
     n 1: a line generated by a point on one figure rolling around a
          second figure [syn: {line roulette}]
     2: a wheel with teeth for making a row of perforations [syn: {toothed
        wheel}]
     3: a gambling game in which players bet on which compartment of
        a revolving wheel a small ball will come to rest in