sleeper
B2Informal to neutral. Common in both everyday and specialist contexts (transport, espionage, entertainment).
Definition
Meaning
A person or thing that sleeps, or something that is unexpectedly successful or powerful.
A railway sleeping car; a spy who remains undercover for a long time before activation; a film, book, or investment that achieves unexpected success; a hidden structural support beam; a small earring worn to keep a piercing hole open.
Linguistics
Semantic Notes
Highly polysemous. The meaning is heavily dependent on context. The core metaphorical link is 'inactivity followed by significant activity or impact'.
Dialectal Variation
British vs American Usage
Differences
UK prefers 'sleeper' for the railway car and the small earring (sleeper earring). US uses 'sleeper' more broadly for all senses, but 'Pullman car' is a historical synonym for the railway sense. The espionage sense is equally common in both.
Connotations
In UK, 'sleeper' in transport is a standard, neutral term. In both, 'sleeper hit' in entertainment carries positive surprise. The spy sense is serious and covert.
Frequency
The 'unexpected success' sense is slightly more frequent in US media/colloquial speech. The structural beam sense is technical and equally used.
Vocabulary
Collocations
Grammar
Valency Patterns
[be] a sleeper[function/act] as a sleeper[discover/uncover] a sleeper[become/emerge as] a sleeperVocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Phrases
Idioms & Phrases
- “a sleeper hit”
- “to plant a sleeper”
- “to wake a sleeper (spy)”
Usage
Context Usage
Business
Refers to an investment or product that initially underperforms but later yields high returns.
Academic
Used in political science/history for long-term undercover operatives; in film/literary studies for unexpectedly successful works.
Everyday
Most commonly refers to a person who sleeps in a certain way ('a light sleeper') or a surprisingly good film.
Technical
In rail transport: a transverse support for tracks. In construction: a horizontal load-bearing beam.
Examples
By Part of Speech
verb
British English
- This train sleepers all the way to Scotland.
American English
- We decided to sleeper our way across the country.
adverb
British English
- This phrase is not used adverbially.
American English
- This phrase is not used adverbially.
adjective
British English
- They offer a sleeper service to Penzance.
- It was a sleeper issue in the election.
American English
- He bought a sleeper sofa for the apartment.
- The team is a sleeper pick for the championship.
Examples
By CEFR Level
- My brother is a heavy sleeper.
- We took the sleeper train to Edinburgh.
- That film was a real sleeper hit last year.
- I need to buy some new sleeper earrings.
- The intelligence agency discovered a sleeper cell operating in the capital.
- The old railway sleepers were reused for garden landscaping.
- The novel remained a cultural sleeper for decades before critics reevaluated it.
- The economic policy acted as a sleeper, its full impact not felt until the following parliamentary term.
Learning
Memory Aids
Mnemonic
Think of a bear in hibernation (a sleeper) – it's inactive for a long time, then wakes up powerful. This captures the core idea of hidden potential or function.
Conceptual Metaphor
INACTIVITY IS POTENTIAL (a sleeper holds unseen power); SECRECY IS SLEEP (a spy 'sleeps' until activated).
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Не переводите 'sleeper hit' как 'спящий удар'. Это 'неожиданный/темный хит'.
- 'Sleeper agent' — 'агент-нелегал' или 'законсервированный агент', а не 'спящий агент' (букв.).
- 'Sleeper' (поезд) — 'спальный вагон', а не 'спальник' (sleeping bag).
Common Mistakes
- Using 'sleeper' to mean 'someone who is sleepy' (use 'sleepy person').
- Confusing 'sleeper' (train) with 'sleeper' (spy) without clear context.
- Saying 'sleeper' for a baby who sleeps well (prefer 'good sleeper').
Practice
Quiz
In the context of rail transport in the UK, what is a 'sleeper'?
FAQ
Frequently Asked Questions
No, it's more commonly used for things (trains, films, spies, beams) than for people. For a person, it's usually specified (e.g., 'a sound sleeper').
They are close synonyms for 'unexpected success'. 'Dark horse' is used almost exclusively for people or teams in competitions. 'Sleeper' is broader, applying to films, books, stocks, etc.
Rarely and informally. It can mean 'to travel by sleeper train' (e.g., 'We sleepered to Vienna'). This is not standard formal usage.
No. In this context, 'cell' refers to a small, covert group of operatives (e.g., spies or terrorists). A 'sleeper cell' is one that remains dormant until activated.
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