Source : Webster's Revised Unabridged Dictionary (1913)

Backgammon \Back"gam`mon\, n. [Origin unknown; perhaps fr. Dan.
   bakke tray + E. game; or very likely the first part is from
   E. back, adv., and the game is so called because the men are
   often set back.]
   A game of chance and skill, played by two persons on a
   ``board'' marked off into twenty-four spaces called
   ``points''. Each player has fifteen pieces, or ``men'', the
   movements of which from point to point are determined by
   throwing dice. Formerly called tables.

   {Backgammon board}, a board for playing backgammon, often
      made in the form of two rectangular trays hinged together,
      each tray containing two ``tables''.

Source : WordNet®

backgammon board
     n : the board on which backgammon is played