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
Coaches who’ve had to face either unit understand the sleepless nights both can cause.
—Dallas News, 17 Nov. 2022
Maybe this memory inspired one of those sleepless nights in Taylor Swift’s life.
—Vulture, 28 Oct. 2022
These little things have caused me no end of sleepless nights, emotional anguish, and personal turmoil.
—Jaina Grey, WIRED, 2 Dec. 2022
The album, which sees the singer reminisce on 13 sleepless nights throughout her life, marks both a return to pop and a return to more personal subject matter for Swift.
—Lauren Huff, EW.com, 25 Oct. 2022
See More
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
Coaches who’ve had to face either unit understand the sleepless nights both can cause.
—Dallas News, 17 Nov. 2022
Maybe this memory inspired one of those sleepless nights in Taylor Swift’s life.
—Vulture, 28 Oct. 2022
These little things have caused me no end of sleepless nights, emotional anguish, and personal turmoil.
—Jaina Grey, WIRED, 2 Dec. 2022
The album, which sees the singer reminisce on 13 sleepless nights throughout her life, marks both a return to pop and a return to more personal subject matter for Swift.
—Lauren Huff, EW.com, 25 Oct. 2022
See More
These examples are programmatically compiled from various online sources to illustrate current usage of the word 'sleepless.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.
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
Dictionary Entries Near sleepless
Cite this Entry
“Sleepless.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/sleepless. Accessed 6 Dec. 2023.
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Kids 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
More from Merriam-Webster on sleepless
Nglish: Translation of sleepless for Spanish Speakers
Britannica English: Translation of sleepless for Arabic Speakers
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