Source : Webster's Revised Unabridged Dictionary (1913)

Double-decker \Dou"ble-deck"er\, n.
   (a) A tenement house having two families on each floor.
       [Local, U. S.]
   (b) A biplane a["e]roplane or kite. [Colloq.]

Double-decker \Dou"ble-deck"er\, n.
   1. (Naut.) A man-of-war having two gun decks.

   2. A public conveyance, as a street car, with seats on the
      roof. [Colloq.]

Source : WordNet®

double-decker
     n : a vehicle carrying many passengers; used for public
         transport; "he always rode the bus to work" [syn: {bus},
         {autobus}, {coach}, {charabanc}, {jitney}, {motorbus}, {motorcoach},
          {omnibus}]