sleepless
Americanadjective
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without sleep.
a sleepless night.
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watchful; alert.
sleepless devotion to duty.
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always active.
the sleepless ocean.
adjective
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without sleep or rest
a sleepless journey
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unable to sleep
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always watchful or alert
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poetic always active or moving
the sleepless tides
Other Word Forms
Etymology
Origin of sleepless
late Middle English word dating back to 1375–1425; see origin at sleep, -less
Explanation
If something is sleepless, it's wakeful or restless, like a sleepless night spent in an unfamiliar house listening to spooky noises. You might be sleepless the night before an exciting trip, or sleepless in your sleeping bag because the ground feels cold and hard beneath you. Whenever sleep won't come—because of worry, excitement, or discomfort—you can describe yourself (and the night) as sleepless. It's used in a literary way as well, to mean "restless" or "constantly moving," like a sleepless willow tree swaying in the breeze.
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
“It’s been very disabling at work, with friends, with family — a lot of sleepless nights.”
From Los Angeles Times • May 5, 2026
"I will now be busy throughout the day," the visibly tired driver told AFP, his eyes red and heavy after the sleepless night.
From Barron's • Apr. 21, 2026
Speaking to BBC Newsday Moroccan journalist Jalal Bounour said that it was "a sleepless night as fans welcomed the news with great excitement and joy".
From BBC • Mar. 18, 2026
They simply show that a disciplined, diversified approach offers something rare in investing: higher odds of success with fewer sleepless nights.
From MarketWatch • Feb. 5, 2026
Sarai watched them all, the sleeping and the sleepless.
From "Strange the Dreamer" by Laini Taylor
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
