sleep·​less | \ ˈslēp-ləs How to pronounce sleepless (audio) \

Definition of sleepless

1 : not able to sleep lay sleepless with fever
2 : affording no sleep sleepless nights
3 : unceasingly active or operative sleepless casinos

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Other Words from sleepless

sleeplessly adverb
sleeplessness noun

Examples of sleepless in a Sentence

He lay sleepless in bed.
Recent Examples on the Web The cast could have piled off the F train after a sleepless night. National Geographic, "The idea of beauty is always shifting. Today, it’s more inclusive than ever.," 7 Jan. 2020 The scenario is enough to give most coaches sleepless nights. Michelle Gardner, azcentral, "ASU's true freshmen linemen show growth over tough first season," 23 Dec. 2019 One day, after a sleepless night, Bordeaux fell asleep at his post — a serious offense. T. Christian Miller, ProPublica, "The Navy installed touch-screen steering systems to save money.," 20 Dec. 2019 But the long hours and sleepless nights didn’t yield agreement on the last piece of the Paris Agreement’s rulebook: guidelines for how international carbon markets would serve the 2015 climate deal. Jean Chemnick, Scientific American, "U.N. Climate Talks Limp to a Disappointing Close," 16 Dec. 2019 Many sleepless nights followed with Sigler pondering the beauty of the car vs. the high price. Vern Parker, Houston Chronicle, "1940 Chevrolet Special Deluxe is dream convertible," 13 Dec. 2019 Carson Wentz is set to have plenty more sleepless nights, but the Eagles star will be up late for an amazing reason. Glenn Erby, Eagles Wire, "Eagles QB Carson Wentz and wife are expecting their first child," 28 Nov. 2019 Just before 8 that morning, almost exactly 12 hours after the cyberattack on the Olympics had begun, Oh and his sleepless staffers finished reconstructing their servers from backups and began restarting every service. Krista Stevens, Longreads, "Olympic Destroyer: The Cyberattack on the 2018 Winter Games," 24 Oct. 2019 Was my partner secretly waking me up at night in order to turn me in to a sleepless zombie? Marc Davila, House Beautiful, "Why Switching to an Emma Mattress Helped Me Sleep Better Than Ever," 1 Aug. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'sleepless.' 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 sleepless

15th century, in the meaning defined at sense 1

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Time Traveler for sleepless

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The first known use of sleepless was in the 15th century

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Statistics for sleepless

Last Updated

11 Jan 2020

Cite this Entry

“Sleepless.” The Dictionary, Merriam-Webster Inc., Accessed 20 January 2020.

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More Definitions for sleepless


How to pronounce sleepless (audio)

English Language Learners Definition of sleepless

: without sleep
: not able to sleep


sleep·​less | \ ˈslē-pləs How to pronounce sleepless (audio) \

Medical Definition of sleepless

: not able to sleep : insomniac

Other Words from sleepless

sleeplessness noun

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Comments on sleepless

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


not to be intimidated or subdued

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