Double-decker /(?)/

Dou·ble-deck·er

Double-decker

n.
  1. A man-of-war having two gun decks. (Naut.)
  2. A tenement house having two families on each floor. [Local, U. S.]
  3. anything having two decks or levels, as a bus with two levels for passengers. In older vehicles, less often today, the upper deck was open, as on street cars. [Colloq.]