Meaning of “sleeper” - Learner’s Dictionary

sleeper

noun uk us /ˈsliːpər/
a light/heavy sleeper

someone who wakes up easily/does not wake up easily

TRAIN [ C ]

a train or a part of a train that has beds in it

SUPPORT [ C ] UK (US railroad tie)

a piece of wood that is used to support a railway track (= the thing a train moves along on)

JEWELLERY [ C ] UK

a small gold or silver ring worn in the ear

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