sleeper
Word family noun sleep sleeper sleepiness sleeplessness sleepingsleeping bagsleeping carsleeping partnersleeping pillsleeping policemansleeping sicknesssleepoutsleepwalkersleepwalkingsleepyheadadjective asleep sleepless sleepy sleeperyverb sleep sleepwalkadverb sleepily sleeplessly
Trains & railways
sleep·er /ˈsliːpə $ -ər/ noun [countableC] 1 someone who sleeps in a particular way 睡得…的人
light sleeper (=someone who wakes easily) 睡得不熟的人，易醒的人
heavy sleeper (=someone who does not wake easily) 睡得很熟的人，不易醒的人
2. someone who is asleep 在睡觉的人
3. 
British EnglishBrETTT a heavy piece of wood or concrete that supports a railway track 〔铁路的〕枕木，轨枕 SYN American English tie
British EnglishBrETTT a heavy piece of wood or concrete that supports a railway track 〔铁路的〕枕木，轨枕 SYN American English tie4 TTT
a) a night train with carriages that have beds for passengers to sleep in 卧铺列车
b) a sleeping car 卧铺车厢
c) American EnglishAmE a bed on a train for a passenger to sleep in 〔火车的〕卧铺
5. especially American EnglishAmE a film, book etc which is successful, even though people did not expect it to be 爆冷门的影片[书籍等]
6. American EnglishAmE a piece of clothing for a baby that covers its whole body including its feet 〔一直包到脚的〕婴儿睡袋
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 潜伏特工，潜伏的间谍
Examples from the Corpus
sleeper• She's good at that too, an accomplished sleeper, with childish face.• People who say they are disturbed by noise at night may just happen to be light sleepers.• Many sleepers are disturbed by light that pervades their eyelids when they have their eyes closed.• Often what is perceived as insomnia by an older sleeper is only a change in sleep length and sleep quality.• He's a restless sleeper, kicking and thrashing about throughout the night.• He had booked on tomorrow night's sleeper, and would head up to Oban on Friday.• The air exerts pressure on the airway, holding it open and allowing the sleeper to breathe normally.
heavy sleeper• Or else she had become a heavy sleeper over the years.• Mrs Fairfax is a heavy sleeper, like most old people, and didn't hear anything.• Some people who sleep next to snorers are able to tune out the sound, if they are heavy sleepers.
From Longman Business Dictionary
sleepersleep·er /ˈsliːpə-ər/ noun [countableC] American EnglishAmEFINANCEMARKETING
a share or a product that is not successful immediately, but then suddenly starts to sell well or be successful
The movie turned out to be a sleeper.