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
And one lively female was virtually sleepless, averaging just four minutes of sleep each day.
—
Amber Jorgenson, Discover Magazine, 20 Feb. 2019
Practical and Cute Enter the perfect solution to her sleepless nights.
—Amanda Garrity, Good Housekeeping, 25 Jan. 2023
Stephen King penned the screenplay for this seminal horror anthology, featuring five freakish stories to give you sleepless nights.
—Declan Gallagher, EW.com, 19 Jan. 2023
So Good got me through hours of travel, moments with friends, and sleepless nights.
—Rolling Stone, 27 Dec. 2022
See All Example Sentences for sleepless
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Amber Jorgenson, Discover Magazine, 20 Feb. 2019
Practical and Cute Enter the perfect solution to her sleepless nights.
—Amanda Garrity, Good Housekeeping, 25 Jan. 2023
Stephen King penned the screenplay for this seminal horror anthology, featuring five freakish stories to give you sleepless nights.
—Declan Gallagher, EW.com, 19 Jan. 2023
So Good got me through hours of travel, moments with friends, and sleepless nights.
—Rolling Stone, 27 Dec. 2022
See All Example Sentences for sleepless
Cite this Entry
“Sleepless.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/sleepless. Accessed 18 Jul. 2025.
Copy CitationKids Definition
sleepless
adjective
sleep·less
ˈslē-pləs 
1
: not able to sleep
2
: marked by the absence of sleep
a sleepless night
3
: unceasingly alert or active
sleeplessly
adverb
sleeplessness
noun
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