sleeper

B1 · Intermediate Countable noun

n. a train carriage that has beds for passengers to sleep in during a long journey.

n. a railroad car equipped with berths or compartments for passengers to sleep in.

“We booked a sleeper for the overnight trip from London to Edinburgh.”

“Traveling by sleeper allowed the consultants to arrive in the capital refreshed and ready for their morning presentations.”

B2 · Upper Intermediate Countable noun

n. a book, movie, or product that becomes a big success after being ignored for a long time.

n. a commercial or artistic work that achieves significant success only after a period of relative obscurity.

“The low-budget horror movie was the sleeper hit of the summer.”

“Industry analysts were stunned when the indie title became a sleeper success, eventually outselling the year's most anticipated blockbusters.”

B2 · Upper Intermediate Countable noun

n. a spy who lives a normal life in a country and waits for a long time before starting their secret work.

n. an agent or spy placed in a target country or organization to remain dormant until activated for a specific mission.

“The police discovered that the quiet neighbor was actually a sleeper for a foreign agency.”

“Intelligence officials suspected that several sleepers had been embedded within the tech firm years before the data breach occurred.”

B2 · Upper Intermediate Countable noun British English

n. the heavy pieces of wood or concrete that support the metal tracks of a railway.

n. a rectangular support for the rails in railroad tracks, typically made of treated wood, concrete, or steel.

“Workers were busy replacing the old wooden sleepers with new concrete ones.”

“The derailment was attributed to the degradation of the wooden sleepers, which had rotted after decades of exposure to the elements.”

C1 · Advanced Countable noun Slang

n. a car that looks like a normal, slow car but has a very powerful engine inside.

n. a vehicle that has been high-performance modified but retains an unassuming, stock exterior to deceive others about its speed.

“His old family sedan is a total sleeper; it can beat most sports cars in a race.”

“He took pride in his sleeper, enjoying the look of shock on other drivers' faces when his rusted hatchback left them behind at the light.”

B2 · Upper Intermediate Countable noun American English

n. a one-piece suit for a baby or child to wear while sleeping, often covering the feet.

n. a one-piece set of pajamas for an infant or young child, usually featuring enclosed feet.

“The baby looked adorable in his blue fleece sleeper.”

“She bought a set of cotton sleepers for the newborn, ensuring they had snap closures for easier diaper changes at night.”

C1 · Advanced Countable noun Medicine Slang · Informal

n. a pill that helps you fall asleep.

n. a pharmacological agent, such as a sedative or hypnotic, administered to induce sleep.

“He had to take a sleeper to deal with his jet lag after the long flight.”

“The doctor warned against the long-term use of sleepers, citing the risk of dependency and altered sleep cycles.”