sleep

American  

[sleep] / slip /

verb (used without object)

slept, sleeping

1. to take the rest afforded by a suspension of voluntary bodily functions and the natural suspension, complete or partial, of consciousness; cease being awake.

   Synonyms:

   doze , drowse , nap , slumber

2. Botany.  to assume, especially at night, a state similar to the sleep of animals, marked by closing of petals, leaves, etc.

3. to be dormant, quiescent, or inactive, as faculties.

4. to be careless or unalert; allow one's alertness, vigilance, or attentiveness to lie dormant.

   While England slept, Germany prepared for war.

5. to lie in death.

   They are sleeping in their tombs.

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verb (used with object)

slept, sleeping

1. to take rest in (a specified kind of sleep).

   He slept the sleep of the innocent.

2. to accommodate for sleeping; have sleeping accommodations for.

   This trailer sleeps three people.

3. to spend or pass in sleep (usually followed by away orout ).

   to sleep the day away.

4. to recover from the effects of (a headache, hangover, etc.) by sleeping (usually followed by off oraway ).

noun

1. the state of a person, animal, or plant that sleeps.

   Synonyms:

   repose , rest

2. a period of sleeping.

   a brief sleep.

   Synonyms:

   nap

3. dormancy or inactivity.

4. the repose of death.

5. sleeper.

verb phrase

1. sleep together  to be sexual partners; have a sexual relationship.

2. sleep around  to have sexual relations with many partners, especially in a casual way; be sexually promiscuous.

3. sleep over  to spend one or more nights in a place other than one's own home.

   Two friends will sleep over this weekend.

4. sleep out

   1. (especially of domestic help) to sleep away from one's place of employment.

   2. Chiefly Northern U.S.  to sleep away from one's home.

   3. to sleep outdoors.

5. sleep on  to postpone making a decision about for at least a day.

   to sleep on a proposal till the end of the week.

6. sleep in

   1. (especially of domestic help) to sleep where one is employed.

   2. to sleep beyond one's usual time of arising.

7. sleep with  to have sexual relations with.

idioms

1. put to sleep,  to put (an animal) to death in a humane way.

   to put a sick old dog to sleep.

sleep British  

/ sliːp /

noun

1. a periodic state of physiological rest during which consciousness is suspended and metabolic rate is decreased See also paradoxical sleep

2. botany the nontechnical name for nyctitropism

3. a period spent sleeping

4. a state of quiescence or dormancy

5. a poetic or euphemistic word for death

6. informal  the dried mucoid particles often found in the corners of the eyes after sleeping

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verb

1. (intr) to be in or as in the state of sleep

2. (intr) (of plants) to show nyctitropism

3. (intr) to be inactive or quiescent

4. (tr) to have sleeping accommodation for (a certain number)

   the boat could sleep six

5. to pass (time) sleeping

6. (intr) to fail to pay attention

7. poetic  (intr) to be dead

8. to give (something) extended consideration, esp overnight

sleep Scientific  

/ slēp /

1. 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.

2. See also non-REM sleep REM sleep

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sleep More Idioms  

More idioms and phrases containing sleep

• asleep
• let sleeping dogs lie
• lose sleep over
• put to sleep

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Other Word Forms

• antisleep adjective
• sleepful adjective
• sleeplike adjective
• undersleep verb (used without object)

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

Example Sentences

My husband either wakes up at 5:30 and works out, or I’ll give him an extra hour of sleep.

From The Wall Street Journal

In September 2025, the charity worked with 176 people sleeping rough - it said this was the highest number of people it has ever recorded in one month.

From BBC

At another settlement, the U.N. refugee agency has run out of blankets, tarpaulins and sleeping mats, forcing refugees to sleep in the open.

From The Wall Street Journal

That morning, the workers had teased them for not showing up early to help, but Angel had wanted to sleep in.

From Los Angeles Times

Medical experts have long questioned the diagnostic value of Amen’s scans, noting that reduced frontal-lobe activity can be influenced by fatigue, stress, sleep deprivation or even the scanning method itself.

From Salon

Related Words

• bed down
• doze
• fall asleep
• languish
• relax
• snooze