sleep‧er /ˈsliːpə $ -ər/ noun [countable]
[Word Family: noun: sleep, sleeper, sleepiness, sleeplessness; adjective: asleep, sleepless, sleepy; adverb: sleepily, sleeplessly; verb: sleep]

1. someone who sleeps in a particular way
light sleeper (=someone who wakes easily)
heavy sleeper (=someone who does not wake easily)

2. someone who is asleep

3.
British English a heavy piece of wood or concrete that supports a railway track Synonym : tie American English

4.
a) a night train with carriages that have beds for passengers to sleep in
b) a sleeping car
c) American English a bed on a train for a passenger to sleep in

5. especially American English a film, book etc which is successful, even though people did not expect it to be

6. American English a piece of clothing for a baby that covers its whole body including its feet

7. a spy who is sent to a particular place and who lives an ordinary life there until a later time, when they begin their spying activities

[TahlilGaran] Dictionary of Contemporary English ▲