double-decker

Short definition from Wiktionary

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
   Any object with two layers or parts stacked on top of each other.
4. 4
   Any object with two layers or parts stacked on top of each other: A sandwich with three slices of bread, whose toppings are on both sides of the middle slice.
5. 5
   A headline that is two lines long.
6. 6
   a man who both penetrates (top) and is penetrated (bottom) in sex with other men; sometimes also has relationships with women and/or presents masculine as well as feminine mannerisms and appearances.
7. 7
   Alternative spelling of double-decker.