Meaning of “deck” - Learner’s Dictionary

deck

noun [ C ] uk us /dek/
SHIP/BUS/PLANE

B2 one of the floors of a ship, bus, or aircraft:

The children like to sit on the top deck of the bus.
on deck

on the top floor of a ship that is not covered

CARDS US (UK/US pack)

a collection of cards that you use to play a game

MACHINE

a machine that you use to play records or tapes (= plastic cases containing magnetic material used to record sounds):

a tape deck

(Definition of “deck” from the Cambridge Learner’s Dictionary © Cambridge University Press)