-
Sleep
Sleep is a naturally recurring state of mind and body, characterized by altered consciousness, relatively inhibited sensory activity, reduced muscle activity and inhibition of nearly all voluntary muscles during rapid eye movement (REM) sleep, and reduced interactions with surroundings. It is distinguished from wakefulness by a decreased ability to react to stimuli, but more reactive than coma or disorders of consciousness, sleep displaying very different and active brain patterns.
Sleep occurs in repeating periods, in which the body alternates between two distinct modes: REM sleep and non-REM sleep. Although REM stands for “rapid eye movement”, this mode of sleep has many other aspects, including virtual paralysis of the body. A well-known feature of sleep is the dream, an experience typically recounted in narrative form, which resembles waking life while in progress, but which usually can later be distinguished as fantasy.
During sleep, most of the body’s systems are in an anabolic state, helping to restore the immune, nervous, skeletal, and muscular systems; these are vital processes that maintain mood, memory, and cognitive function, and play a large role in the function of the endocrine and immune systems. The internal circadian clock promotes sleep daily at night. The diverse purposes and mechanisms of sleep are the subject of substantial ongoing research.Sleep is a highly conserved behavior across animal evolution.Humans may suffer from various sleep disorders, including dyssomnias such as insomnia, hypersomnia, narcolepsy, and sleep apnea; parasomnias such as sleepwalking and REM behavior disorder; bruxism; and circadian rhythm sleep disorders. The advent of artificial light has substantially altered sleep timing in industrialized countries.
-
Hibernate (verb)
To spend winter time in hibernation.
-
Hibernate (verb)
To live in seclusion.
-
Hibernate (verb)
To enter a standby state which conserves power without losing the contents of memory.
-
Sleep (verb)
To rest in a state of reduced consciousness.
“You should sleep 8 hours a day.”
-
Sleep (verb)
To spin on its axis with no other perceptible motion.
“When a top is sleeping, it is spinning but not precessing.”
-
Sleep (verb)
To cause (a spinning top or yo-yo) to spin on its axis with no other perceptible motion.
-
Sleep (verb)
To accommodate in beds.
“This caravan can sleep up to four people.”
-
Sleep (verb)
To be slumbering in (a state).
“to sleep a dreamless sleep”
-
Sleep (verb)
To be careless, inattentive, or unconcerned; not to be vigilant; to live thoughtlessly.
-
Sleep (verb)
To be dead; to lie in the grave.
-
Sleep (verb)
To be, or appear to be, in repose; to be quiet; to be unemployed, unused, or unagitated; to rest; to lie dormant.
“a question sleeps for the present; the law sleeps”
-
Sleep (verb)
To wait for a period of time without performing any action.
“After a failed connection attempt, the program sleeps for 5 seconds before trying again.”
-
Sleep (noun)
The state of reduced consciousness during which a human or animal rests in a daily rhythm.
“I really need some sleep.”
“We need to conduct an overnight sleep test to diagnose your sleep problem.”
-
Sleep (noun)
An act or instance of sleeping.
“I’m just going to have a quick sleep.”
-
Sleep (noun)
A night.
“There are only three sleeps till Christmas!”
-
Sleep (noun)
Rheum, crusty or gummy discharge found in the corner of the eyes after waking, whether real or a figurative objectification of sleep (in the sense of reduced consciousness).
“sleepy|q1=informal|sleeper|q2=informal|sleepy dust|q3=informal|crusty|q4=slang|gound|q5=UK dialectal”
“Wipe the sleep from your eyes.”
-
Sleep (noun)
A state of plants, usually at night, when their leaflets approach each other and the flowers close and droop, or are covered by the folded leaves.
“nyctinasty|nyctitropism”
-
Sleep (noun)
The hibernation of animals.