sleep·​er | \ ˈslē-pər How to pronounce sleeper (audio) \

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

Fae Healy awoke at 3 in the morning and immediately knew something was wrong — her husband, Patrick, a sound sleeper, was not in bed. Thomas Gerencer,, "Ticks: They’re not just for hikers anymore," 23 Aug. 2019 In order to determine the prevalence of advanced sleepers, the researchers analyzed data from more than 2,400 patients at a sleep disorder clinic., "Are you an ‘extreme early bird’?," 20 Aug. 2019 Another company, Kids II, also recalled its inclined sleeper after it was associated with five deaths. Washington Post, "House committee launches investigation into inclined sleepers tied to infant deaths," 14 Aug. 2019 With NCAA Tournament Selection Sunday in the books, here's a prediction for each region, a National Champion selection and one intriguing sleeper to watch that could become this year's Cinderella. Sean Meagher,, "Live score updates: Ohio State vs. South Dakota State in men's NCAA Tournament 2018," 14 Mar. 2018 But light sleepers, take note: The pool restaurant/bar is at the center of the property and stays open until 11 p.m., so pack earplugs. Susannah Rigg, Condé Nast Traveler, "19 Best Boutique Hotels in Mexico City," 27 Feb. 2018 The Beautyrest Recharge Dawson 121/2-inch hybrid firm mattress ($1,299-$1,999, works well for those sharing beds with restless sleepers because the memory foam won’t move around as much, Meshberg says. Eustacia Huen, Twin Cities, "Can’t sleep? You probably need to make these changes.," 9 Aug. 2019 Another company, Kids II, also recalled some 694,000 sleepers in April after five infant deaths. CBS News, "Despite recall, some day care centers still using inclined sleepers blamed in infant deaths," 9 Aug. 2019 The Rock ’n Play inclined sleeper should be removed from the market immediately. Stephie Grob Plante, Vox, "The Rock ’n Play was recalled after it was linked to 32 infant deaths. It’s still used at some daycares.," 8 Aug. 2019

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

27 Aug 2019

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 How to pronounce sleeper (audio) \

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

What made you want to look up sleeper? Please tell us where you read or heard it (including the quote, if possible).


formidable, illustrious, or eminent

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