sleep·​er | \ˈslē-pər \

Definition of sleeper 

1 : one that sleeps

2 : a piece of timber, stone, or steel on or near the ground to support a superstructure, keep railroad rails in place, or receive floor joists : stringpiece

4 : someone or something unpromising or unnoticed that suddenly attains prominence or value the low-budget film became the summer's sleeper

5 : children's pajamas usually with feet usually used in plural

6 chiefly British : a small earring or stud worn to keep the hole of a pierced ear from closing

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Synonyms for sleeper


dozer, slumberer

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Examples of sleeper in a Sentence

Sleepers were awakened by the sound of a loud crash. He may turn out to be the sleeper in this year's election. The movie was the summer's sleeper. The movie became the sleeper hit of the summer.
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Recent Examples on the Web

The beep or buzz of the cell phone indicating that a call has come in awakens the sleeper, who instinctively reaches over and responds to the message. Brittney Mcnamara, Teen Vogue, "College Students Are Sleep Texting Potentially Embarrassing Things," 5 Dec. 2018 Potential sleeper team Experience tends to come in handy in big tournaments, and 17 of the 23 players on Costa Rica’s roster have at least 35 caps. Daniel Rapaport,, "2018 World Cup Group E Preview: It's Brazil and Three Challengers for Second," 8 June 2018 Ideal for sleepers with neck or back pain but equally well-suited for anyone who wants to enjoy a great night's sleep, this best-selling memory foam pillow disperses body heat in order to deliver cooling comfort to your neck and upper back. Popular Mechanics, "This Memory Foam Pillow Keeps You Cool While You Sleep," 10 Oct. 2018 The Barkley pick, the McKinnon pick and the Engram pick were my personal favorites, with Ridley as a late-round sleeper with high upside. Staff,, "Fantasy Football 2018 Mock Draft," 4 July 2018 Know a buzz horse among the Derby contenders Every year, there are a couple horses, besides the favorite, getting a lot of buzz and seen by bettors as possible sleepers. Allison Ross, The Courier-Journal, "Don't want to sound like a Derby newbie? Use these 8 tips and you'll be an instant insider," 31 Mar. 2018 But in the last three weeks before November’s midterm elections, re-election for Ms. Herrera Beutler (R., Wash.) is looking shakier, one of a handful of sleeper House races that have grown increasingly competitive down the final stretch. Kristina Peterson, WSJ, "House Races Tighten as Midterm Elections Near," 16 Oct. 2018 Fairmont Kea Lani, Maui The Fairmont Kea Lani is an all suite and villa resort that spans 22 oceanfront acres and includes family-friendly one-bedroom suites—starting around 860 square feet—equipped with sleeper sofas, microwaves, and balconies. Cnt Editors, Condé Nast Traveler, "The Best Resorts in Hawaii: 2018 Readers' Choice Awards," 9 Oct. 2018 First among them — and the most indulgent, in my opinion — is the aforementioned sleeper car. Vlad Savov, The Verge, "Volvo’s 360c concept has softened my cynicism about autonomous cars," 6 Sep. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'sleeper.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of sleeper

12th century, in the meaning defined at sense 1

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Statistics for sleeper

Last Updated

17 Dec 2018

Look-up Popularity

Time Traveler for sleeper

The first known use of sleeper was in the 12th century

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More Definitions for sleeper



English Language Learners Definition of sleeper

: a person who sleeps in a particular way

: someone who is asleep

: a place or piece of furniture that can be used for sleeping


sleep·​er | \ˈslē-pər \

Kids Definition of sleeper

1 : someone that sleeps I'm a light sleeper.

2 : a railroad car with berths for sleeping

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More from Merriam-Webster on sleeper

Rhyming Dictionary: Words that rhyme with sleeper

Thesaurus: All synonyms and antonyms for sleeper

Spanish Central: Translation of sleeper

Nglish: Translation of sleeper for Spanish Speakers Encyclopedia article about sleeper

Comments on sleeper

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