sleeper

UK: ˈsliːpə | US: ˈslipər

Definition

  1. n. a person or animal that is asleep

  2. n. something with hidden potential or unexpected success (e.g., a "sleeper hit")

  3. n. a type of train carriage with beds for overnight travel

Structure
sleep <to rest in a state of unconsciousness>er <noun suffix indicating "one who does">
Etymology

The word "sleeper" originates from Old English "slǣpan" (to sleep), combined with the agentive suffix "-er," which denotes "one who performs an action." Over time, it evolved to describe not only a person who sleeps but also objects or concepts with latent qualities (e.g., a "sleeper" train or a "sleeper" movie). The suffix "-er" is productive in English, often forming nouns from verbs.

Examples

  1. The baby is a heavy sleeper and rarely wakes up at night.

  2. That indie film turned out to be a sleeper, earning millions unexpectedly.

  3. We booked a sleeper on the overnight train to Edinburgh.

  4. The spy was a sleeper agent, living undercover for years.

  5. The old car in the garage might be a sleeper—it looks plain but has a powerful engine.