sleep
Americanverb (used without object)
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sleeps,
present (3rd person singular)
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slept,
past participle, past
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sleeping
present participle
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to take the rest afforded by a suspension of voluntary bodily functions and the natural suspension, complete or partial, of consciousness; cease being awake.
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Botany. to assume, especially at night, a state similar to the sleep of animals, marked by closing of petals, leaves, etc.
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to be dormant, quiescent, or inactive, as faculties.
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to be careless or unalert; allow one's alertness, vigilance, or attentiveness to lie dormant.
While England slept, Germany prepared for war.
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to lie in death.
They are sleeping in their tombs.
verb (used with object)
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sleeps,
present (3rd person singular)
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slept,
past participle, past
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sleeping
present participle
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to take rest in (a specified kind of sleep).
He slept the sleep of the innocent.
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to accommodate for sleeping; have sleeping accommodations for.
This trailer sleeps three people.
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to spend or pass in sleep (usually followed by away orout ).
to sleep the day away.
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to recover from the effects of (a headache, hangover, etc.) by sleeping (usually followed by off oraway ).
noun
verb phrase
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sleep together to be sexual partners; have a sexual relationship.
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sleep around to have sexual relations with many partners, especially in a casual way; be sexually promiscuous.
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sleep over to spend one or more nights in a place other than one's own home.
Two friends will sleep over this weekend.
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sleep out
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(especially of domestic help) to sleep away from one's place of employment.
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Chiefly Northern U.S. to sleep away from one's home.
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to sleep outdoors.
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sleep on to postpone making a decision about for at least a day.
to sleep on a proposal till the end of the week.
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sleep in
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(especially of domestic help) to sleep where one is employed.
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to sleep beyond one's usual time of arising.
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sleep with to have sexual relations with.
idioms
noun
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a periodic state of physiological rest during which consciousness is suspended and metabolic rate is decreased See also paradoxical sleep
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botany the nontechnical name for nyctitropism
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a period spent sleeping
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a state of quiescence or dormancy
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a poetic or euphemistic word for death
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informal the dried mucoid particles often found in the corners of the eyes after sleeping
verb
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(intr) to be in or as in the state of sleep
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(intr) (of plants) to show nyctitropism
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(intr) to be inactive or quiescent
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(tr) to have sleeping accommodation for (a certain number)
the boat could sleep six
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to pass (time) sleeping
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(intr) to fail to pay attention
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poetic (intr) to be dead
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to give (something) extended consideration, esp overnight
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A natural, reversible state of rest in most vertebrate animals, occurring at regular intervals and necessary for the maintenance of health. During sleep, the eyes usually close, the muscles relax, and responsiveness to external stimuli decreases. Growth and repair of the tissues of the body are thought to occur, and energy is conserved and stored. In humans and certain other animals, sleep occurs in five stages, the first four consisting of non-REM sleep and the last stage consisting of REM sleep. These stages constitute a sleep cycle that repeats itself about five times during a normal episode of sleep. Each cycle is longer that the one preceding it because the length of the REM stage increases with every cycle until waking occurs. Stage I is characterized by drowsiness, Stage II by light sleep, and Stages III and IV by deep sleep. Stages II and III repeat themselves before REM sleep (Stage V), which occurs about 90 minutes after the onset of sleep. During REM sleep, dreams occur, and memory is thought to be organized. In the stages of non-REM sleep, there are no dreams, and brain activity decreases while the body recovers from wakeful activity. The amount and periodicity of sleep in humans vary with age, with infants sleeping frequently for shorter periods, and mature adults sleeping for longer uninterrupted periods.
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See also non-REM sleep REM sleep
Other Word Forms
Derived Forms
Inflected Forms
Participles
Conjugated Forms
Present
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sleepsimple
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sleepssimple
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have sleptperfect
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has sleptperfect
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am sleepingprogressive
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are sleepingprogressive
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is sleepingprogressive
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have been sleepingperfect progressive
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has been sleepingperfect progressive
Past
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sleptsimple
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had sleptperfect
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was sleepingprogressive
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were sleepingprogressive
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had been sleepingperfect progressive
Future
Etymology
Origin of sleep
First recorded before 900; (for the noun) Middle English; Old English slēp (Anglian), slǣp, slāp; cognate with Dutch slaap, German Schlaf, Gothic slēps; (for the verb) Middle English slepen, Old English slēpan, slǣpan, slāpan, cognate with Old Saxon slāpan, Gothic slēpan
Explanation
If you're tired, you probably need to sleep so lie down and close your eyes. When you wake up, you'll feel much better. Everyone needs sleep and most of us get some at least once a day. Maybe that's why sleep is used in so many expressions. If you “sleep on it” you'll wait to make a decision until tomorrow. If you “sleep over,” you stay at someone's place for the night. A person who “lets sleeping dogs lie” knows when not to stir up trouble. If you slip into eternal sleep, you won't be needing any more naps.
Vocabulary lists containing sleep
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.
See Examples For:
"On some days, before I went to sleep, I would think that there'd be a knock on the door tonight and that when I opened, he would be there," Morup's wife told the BBC.
From BBC ● Aug. 8, 2026
"I definitely had nights where I didn't sleep, where I would be awake thinking: 'This is on me. This headline just came out - do the athletes believe that?',"
From BBC ● Aug. 8, 2026
On average, participants entered REM sleep 43 minutes sooner and remained in that stage for about 16 minutes longer.
From Science Daily ● Aug. 7, 2026
One especially noteworthy moment in the 23-minute segment came when Tapper asked if Miller had held his daughter’s blue bunny — which she needs to sleep — hostage.
From Salon ● Aug. 7, 2026
For sleep she partitioned off a cubicle from her writing room just large enough to hold a bed.
From "The Hiding Place" by Corrie ten Boom
State courts have repeatedly ruled that there is no single way to determine where someone lives, and judges must consider multiple factors, such as where a voter sleeps or stores personal belongings.
From Salon ● Jul. 7, 2026
She now sleeps in a plaza near where he worked.
From Barron's ● Jul. 5, 2026
Created by Mindy Kaling, it’s set in New York, the city that never sleeps, not in order to party, but to get something on somebody’s desk first thing in the morning.
From Los Angeles Times ● Jun. 1, 2026
She says there are no English-speakers in her cell, in which she sleeps on a metal bunk.
From BBC ● May 1, 2026
As she sleeps by my side, I pull out of my pocket the lucky eye charm she gave me and pin it inside my T-shirt.
From "Across So Many Seas" by Ruth Behar
Goode had a pet tortoise when he was 6 and slept with a tegu lizard in his bed as a teen.
From Los Angeles Times ● Aug. 6, 2026
In dirty t-shirts and flimsy sandals, hundreds of unaccompanied minors slept outdoors in a disused industrial park in Ceuta after swimming to the Spanish territory from Morocco, AFP saw Saturday.
From Barron's ● Aug. 1, 2026
Participants who maintained regular daily routines tended to experience less pain and depression, regardless of how well they slept.
From Science Daily ● Jul. 31, 2026
They slept in bunk beds and dedicated every waking hour to the cause, garnering thousands of followers on X. They drew up fliers and screen-printed red “Stop AI” shirts.
From The Wall Street Journal ● Jul. 12, 2026
During the worst of it, Mal moved out of her room and into Christopher’s, and they slept side by side, waking when they were tossed against the wooden walls.
From "Impossible Creatures" by Katherine Rundell
In the most recent survey carried out by the Office for Veterans' Affairs, one in 400 ex-service personnel reported they were homeless or sleeping rough.
From BBC ● Aug. 7, 2026
Children sleeping rough were relying on charities and local residents for food and other basic supplies.
From Barron's ● Aug. 6, 2026
Existing drugs manage patients’ symptoms—notably excessive daytime sleepiness and difficulty sleeping at night—rather than the cause.
From The Wall Street Journal ● Aug. 6, 2026
It tore nightclothes from people who had been sleeping moments before.
From Los Angeles Times ● Aug. 6, 2026
You’re so cushy-comfy and sleeping so deeply that you don’t hear that big old truck, hauling two tons of tomatoes, getting closer and closer.
From "Ida B" by Katherine Hannigan
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.
