sleepless

adjective

sleep·​less ˈslēp-ləs How to pronounce sleepless (audio)
1
: not able to sleep
lay sleepless with fever
2
: affording no sleep
sleepless nights
3
: unceasingly active or operative
sleepless casinos
sleeplessly adverb
sleeplessness noun

Examples of sleepless in a Sentence

He lay sleepless in bed.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Alice Cooper discovered his love of entertaining in the Cortez High School cafetorium, returning to the Valley in the ’80s after finding fame and fortune as the rock star most likely to inspire sleepless nights for sheltered parents of Boomers Gone Wild. Ed Masley, AZCentral.com, 23 Oct. 2025 In a way, the first moments in the story between Victor and The Creature are a study of parenthood and the quick madness that ensues from sleepless nights and uncertainty. Billie Melissa, MSNBC Newsweek, 13 Oct. 2025 After enduring a sleepless night while the settlers slept on their library floor, the Khalidi family regrouped in the morning. Ryan Byrnes, Literary Hub, 7 Oct. 2025 Members of the Afghan diaspora spent hours, and sleepless nights, trying to call and text relatives, friends and colleagues back home. Hilary Whiteman, CNN Money, 3 Oct. 2025 See All Example Sentences for sleepless

Word History

First Known Use

15th century, in the meaning defined at sense 1

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

Cite this Entry

“Sleepless.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/sleepless. Accessed 29 Oct. 2025.

Kids Definition

sleepless

adjective
sleep·​less ˈslē-pləs How to pronounce sleepless (audio)
1
: not able to sleep
2
: marked by the absence of sleep
a sleepless night
3
: unceasingly alert or active
sleeplessly adverb
sleeplessness noun

Medical Definition

sleepless

adjective
sleep·​less ˈslē-pləs How to pronounce sleepless (audio)
: not able to sleep : insomniac
sleeplessness noun

More from Merriam-Webster on sleepless

Last Updated: - Updated example sentences
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