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
Derived 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.
For the better part of a year, I spent myriad sleepless nights wrestling with my conscience.
From Salon • Jun. 8, 2026
According to the footage, what awaits Rhaenyra during her reign are fearful subjects, conniving enemies, sleepless nights and plenty of anguish.
From Los Angeles Times • May 29, 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
Passengers touching down at airports in Australia, France, Germany, India, Russia, Taiwan and beyond told of sleepless nights and days-long ordeals to get out of the Middle East when war erupted.
From Barron's • Mar. 4, 2026
In the depths of my sleepless nights I would turn to the Bible for comfort, only to find myself regaled yet again.
From "The Poisonwood Bible" by Barbara Kingsolver
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.
