sleepless
Americanadjective
-
without sleep.
a sleepless night.
-
watchful; alert.
sleepless devotion to duty.
-
always active.
the sleepless ocean.
adjective
-
without sleep or rest
a sleepless journey
-
unable to sleep
-
always watchful or alert
-
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.
Polly Turton, head of climate action at NGO Shade the UK, said the situation was "the new normal. The sleepless nights we're all experiencing, we are going to have to adapt to," she said.
From Barron's ● Jun. 26, 2026
As I emerged from my children’s earliest years—a miasma of Duplo blocks, nursing pads and sleepless nights—I felt utterly depleted, not just in a physical sense but in a creative one.
From The Wall Street Journal ● Jun. 14, 2026
Bleary-eyed from the sleepless nights, she made 29 when she did return against India last month in Bristol.
From BBC ● Jun. 12, 2026
New dads face psychological pressures, from sleepless nights to sky-high bills, which can contribute to postpartum depression.
From Los Angeles Times ● Jun. 10, 2026
I both wished and feared to see Mr. Rochester on the day which followed this sleepless night: I wanted to hear his voice again, yet feared to meet his eye.
From "Jane Eyre" by Charlotte Brontë
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.
