double-decker

/D AH1 B AH0 L D EH0 K ER0/
noun
  1. 1

    A vehicle (usually a bus, coach or train) or aircraft with two floors.

  2. 2

    A frigate with two decks above the waterline.

  3. 3

    (figuratively) Any object with two layers or parts stacked on top of each other.

    โ€œA club sandwich is a double-decker of chicken, ham, lettuce and tomato.โ€

Source: https://en.wiktionary.org/wiki/double-decker