1
: the natural, easily reversible periodic state of many living things that is marked by the absence of wakefulness and by the loss of consciousness of one's surroundings, is accompanied by a typical body posture (such as lying down with the eyes closed), the occurrence of dreaming, and changes in brain activity and physiological functioning, is made up of cycles of non-REM sleep and REM sleep, and is usually considered essential to the restoration and recovery of vital bodily and mental functions
2
: a state resembling sleep: such as
a
: a state of torpid inactivity
c
: the closing of leaves or petals especially at night
d
: a state marked by a diminution of feeling followed by tingling
my foot's gone to sleep
e
: the state of an animal during hibernation
4
: crusty matter present in the corner of an eye upon awakening
slept
ˈslept 
; sleeping; sleeps
; sleeping; sleeps
1
: to rest in a state of sleep
2
: to be in a state (as of quiescence or death) resembling sleep
3
: to have sexual relations
—usually used with with
was sleeping with a coworker
see also sleep together
1
: to be slumbering in
slept the sleep of the dead
2
: to get rid of or spend in or by sleep
sleep away the hours
sleep off a headache
3
: to provide sleeping accommodations for
the boat sleeps six
Synonyms
Examples of sleep in a Sentence
Noun
I just need to get some sleep.
How much sleep did you get last night?
Her roommate talks in her sleep.
The noise woke her from a deep sleep.
He woke up and rubbed the sleep out of his eyes.
Verb
I couldn't sleep last night. I was awake all night long.
I usually try to sleep for at least eight hours every night.
Did you sleep soundly last night?
We were sleeping peacefully when a sudden loud noise woke us up.
I can never sleep on airplanes.
The tent sleeps five adults.
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Recent Examples on the Web
Rachel Murphy, Verywell Health, 17 Nov. 2023
Her husband, two of their daughters, their 10-year-old grandson and Lena’s 87-year-old mother-in-law were stretched out in the same room, silently willing themselves into uneasy sleep.
—Vivian Yee, New York Times, 17 Nov. 2023
This is the safest sleep position but can result in misshapen heads that are flat on the side or back.
—Maria Carter, Parents, 16 Nov. 2023
Researchers used the following checklist to determine how cardiovascular health is connected to aging: diet, physical activity, nicotine exposure, sleep health, BMI, cholesterol, blood sugar, and blood pressure.
—Kaitlin Vogel, Health, 15 Nov. 2023
Apply it overnight for moisturized sleep, or use it as a daytime lip gloss alternative for all-day hydration.
—Samantha Booth, Rolling Stone, 15 Nov. 2023
The Navy has failed to erase the sleep deprivation problems that have been contributing to deadly and expensive accidents aboard American warships, according to a report by the General Accounting Office, the investigative arm of Congress.
—Gary Robbins, San Diego Union-Tribune, 15 Nov. 2023
This absorbing history traces the science of sleep from its origins in a lab at the University of Chicago in the nineteen-twenties.
—Condé Nast, The New Yorker, 13 Nov. 2023
Smoking is the most preventable cause of premature death in the U.S.
Get a healthy amount of sleep.
—Linda Carroll, NBC News, 6 Nov. 2023
Veronica Cristino, Vogue, 21 Nov. 2023
Now is a great time to score a deal on tents, backpacks, sleeping pads, and Garmin devices.
—Scott Gilbertson, WIRED, 20 Nov. 2023
In video captured by NBC News’ crew at the Emirates hospital in Rafah, babies lie side by side, some crying out, while others lie sleeping on their backs or curled up in the fetal position.
—Chantal Da Silva, NBC News, 20 Nov. 2023
This handy sofa bed pulls out to create a much more comfortable sleeping space than an air mattress.
—Matthew Parker, Rolling Stone, 19 Nov. 2023
Instead, many babies develop a flat head from always sleeping on their backs.
—Maria Carter, Parents, 16 Nov. 2023
In the video snippet from November 2021, a man approaches a figure who is sleeping on the sidewalk, holding a large canister, sprays him in the face and flees west.
—Jesse Barron, New York Times, 16 Nov. 2023
Nahid Abdel Hamid, 26, a mother of three, sleeps nearby.
—Hajar Harb, Washington Post, 15 Nov. 2023
As standard, the vessel can sleep up to 10 guests and five crew.
—Rachel Cormack, Robb Report, 8 Nov. 2023
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Noun
Three months of consistent sleep issues is considered insomnia.
—Rachel Murphy, Verywell Health, 17 Nov. 2023
Her husband, two of their daughters, their 10-year-old grandson and Lena’s 87-year-old mother-in-law were stretched out in the same room, silently willing themselves into uneasy sleep.
—Vivian Yee, New York Times, 17 Nov. 2023
This is the safest sleep position but can result in misshapen heads that are flat on the side or back.
—Maria Carter, Parents, 16 Nov. 2023
Researchers used the following checklist to determine how cardiovascular health is connected to aging: diet, physical activity, nicotine exposure, sleep health, BMI, cholesterol, blood sugar, and blood pressure.
—Kaitlin Vogel, Health, 15 Nov. 2023
Apply it overnight for moisturized sleep, or use it as a daytime lip gloss alternative for all-day hydration.
—Samantha Booth, Rolling Stone, 15 Nov. 2023
The Navy has failed to erase the sleep deprivation problems that have been contributing to deadly and expensive accidents aboard American warships, according to a report by the General Accounting Office, the investigative arm of Congress.
—Gary Robbins, San Diego Union-Tribune, 15 Nov. 2023
This absorbing history traces the science of sleep from its origins in a lab at the University of Chicago in the nineteen-twenties.
—Condé Nast, The New Yorker, 13 Nov. 2023
Smoking is the most preventable cause of premature death in the U.S.
Get a healthy amount of sleep.
—Linda Carroll, NBC News, 6 Nov. 2023
Verb
In romantic movies, the couple always falls asleep cuddled together—but in reality, going to sleep is far from bliss for many couples.
—Veronica Cristino, Vogue, 21 Nov. 2023
Now is a great time to score a deal on tents, backpacks, sleeping pads, and Garmin devices.
—Scott Gilbertson, WIRED, 20 Nov. 2023
In video captured by NBC News’ crew at the Emirates hospital in Rafah, babies lie side by side, some crying out, while others lie sleeping on their backs or curled up in the fetal position.
—Chantal Da Silva, NBC News, 20 Nov. 2023
This handy sofa bed pulls out to create a much more comfortable sleeping space than an air mattress.
—Matthew Parker, Rolling Stone, 19 Nov. 2023
Instead, many babies develop a flat head from always sleeping on their backs.
—Maria Carter, Parents, 16 Nov. 2023
In the video snippet from November 2021, a man approaches a figure who is sleeping on the sidewalk, holding a large canister, sprays him in the face and flees west.
—Jesse Barron, New York Times, 16 Nov. 2023
Nahid Abdel Hamid, 26, a mother of three, sleeps nearby.
—Hajar Harb, Washington Post, 15 Nov. 2023
As standard, the vessel can sleep up to 10 guests and five crew.
—Rachel Cormack, Robb Report, 8 Nov. 2023
See More
These examples are programmatically compiled from various online sources to illustrate current usage of the word 'sleep.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.
Word History
Etymology
Noun
Middle English slepe, from Old English slǣp; akin to Old High German slāf sleep and perhaps to Latin labi to slip, slide
First Known Use
Noun
before the 12th century, in the meaning defined at sense 1
Verb
before the 12th century, in the meaning defined at intransitive sense 1
Time Traveler
The first known use of sleep was
before the 12th century
Phrases Containing sleep
Articles Related to sleep
Dictionary Entries Near sleep
Cite this Entry
“Sleep.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/sleep. Accessed 4 Dec. 2023.
Copy Citation
Kids Definition
sleep
1 of 2 noun1
: the natural periodic loss of consciousness during which the powers of the body are restored
2
: a state resembling sleep: as
a
: a state of inactivity (as hibernation) like sleep
b
: death sense 4
put my pet cat to sleep
also
: coma entry 1, trance
c
: a state marked by loss of feeling followed by tingling
my foot's gone to sleep
sleep
2 of 2 verb
slept
ˈslept
; sleeping
; sleeping
1
: to rest or be in a state of sleep
2
: to get rid of or spend in or by sleep
slept off his headache
3
: to provide sleeping space for
the boat sleeps six
4
: to have sexual intercourse
Medical Definition
sleep
1 of 2 noun1
: the natural, easily reversible, periodic state of many living things that is marked by the absence of wakefulness and by the loss of consciousness of one's surroundings, is accompanied by a typical body posture (as lying down with the eyes closed), the occurrence of dreaming, and changes in brain activity and physiological functioning, is made up of cycles of non-REM sleep and REM sleep, and is usually considered essential to the restoration and recovery of vital bodily and mental functions
2
: a state resembling sleep: as
a
: death sense 1
put a pet cat to sleep
b
: a state marked by a diminution of feeling followed by tingling
her foot went to sleep
More from Merriam-Webster on sleep
Nglish: Translation of sleep for Spanish Speakers
Britannica English: Translation of sleep for Arabic Speakers
Britannica.com: Encyclopedia article about sleep
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Merriam-Webster unabridged
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