Vocabulary to describe sleep, naps, and sleep science and health.


Sleep definitions

Sleep (verb) 

1.   To be in a resting state when the body is relaxed and the mind is unconscious.
  • “I couldn’t sleep even though I was so tired.”
  • “We slept quite late last night after the party was over.”
2.   To have enough space or beds for a specific number of people to sleep for the night. 

Usually we would apply this to different types of accommodation like tents and houses, etc.

  • “The studio room sleeps four if you pull out the sofa bed.”
  • “The tent has enough room to sleep six.”

Sleep (noun)

1.   The resting state when the body is relaxed and the mind is unconscious.

 Quite often this is used as part of a common phrase, “get some sleep.”

  • “I’m exhausted. I’m going to get some sleep.”
  • “I finally got some sleep after we finished the project.”
Idiomatic phrases with “sleep”:

Get/go to sleep
– To succeed in sleeping.

  • “She always goes to sleep right after a bedtime story.”
  • “It took me a few hours to get to sleep last night.”

On the verge of sleep
– To come very close to going to sleep.

  • “I was on the verge of sleep when I heard a loud noise.”
2.   A period of sleeping. 

Quite often this is used as part of idiomatic expressions.

  • “Why don’t you have a little sleep before the long drive home?”
  • “I fell into a deep sleep after watching a documentary last night.”
  • “Did you have a good night’s sleep?”
3.   (informal) A way of saying how many nights away something is. 

However, this is not that common.

  • “Two more sleeps until our honeymoon!”

– (noun) The state or condition of being in a state of sleep.

– (adjective) In or relating to the state of sleep.

  • “I enjoy sleeping too much to wake up early on the weekends.”
  • “The sleeping baby lay peacefully in her crib.”

Synonyms of SLEEP

– (adjective) Sleeping or not awake.

  • “The kids were already asleep when I got home.”
Common idiomatic phrases with “asleep”:

Fall asleep
– To start to sleep.

  • “They fell asleep as soon as the movie started.”

Sound/fast asleep
– Completely asleep.

  • “He was sound asleep for the entire journey.”

Half asleep
– Not completely asleep.

  • “I’m usually half asleep until I have my cup of coffee.”

– (verb/noun) To stop being active in order to relax to recover strength.

This is not the same as “sleep” because you do not have to be unconscious to rest. However “sleep” and “nap” are considered “rest,” so it is occasionally used as synonyms and implies a recovery of strength or energy.

  • “You’ll feel better after a good night’s rest.”
  • “She’s resting in the bedroom.”

– (noun, informal) Sleep. 

Although this is considered old-fashioned, I still hear this used from time to time.

  • “I’m looking forward to getting some shuteye when I get home.”

– (verb, noun) Sleep

This is usually used in literature and is not that common in everyday conversation.

  • “She woke up from a long slumber and found herself in a new world.”

Catch/cop/get some z’s
– (American informal expression) To sleep. 

This is not that common in Australia, but I sometimes hear this on American TV shows.

  • “I’m going to catch some z’s in the lounge before my next shift.”

Beauty sleep
– (idiom) Used in a humorous way to refer to the sleep required to feel and look healthy and attractive.

  • “I’m going to need my beauty sleep if I want to look good for tomorrow’s presentation.”

Go to bed
– (phrase) To go to the bed or place where you sleep.

This is often used to mean that one is going to sleep, but it is also used to mean that one physically moves to the bedroom to relax to eventually fall asleep – maybe to read a book, or watch TV.

  • “It’s been a long day. I’m going to bed.”

Turn in
– (phrasal verb, informal) To go to bed.

  • “He usually turns in at about 10pm after watching his favourite TV show.”

– (verb) To go to bed. 

However this is considered more formal and kind of old-fashioned.

  • “She retired early for her big day tomorrow.”

Hit the sack/hay
– (informal American expression) To go to bed. 

This is well-known but not that commonly used.

  • “I’m going to hit the sack before I end up binging the entire show.”

Synonyms of NAP

– (verb/noun) A short sleep, especially during the day.

  • “I usually nap for about half an hour when I get home from my shift.”
  • “I always feel so refreshed after taking a nap.”

Power nap
– (noun) A nap for the purpose of working more effectively for the rest of the day – typically about 15 minutes long.

  • “Companies should make power naps mandatory if they want to increase efficiency.”

– (verb/noun) A short light nap.

Although this is a synonym of “nap,” this is often used to talk about babies napping – maybe because it sounds cuter.

  • “Our baby would catnap throughout the day and then keep us up late at night.”

– (noun) Spanish for a nap, usually taken after lunch.

This is a common tradition in certain countries where the weather is warm and is really only possible where it is okay for businesses to be closed for a long lunch break or the afternoon.

– (verb/noun) Nap.

This is not that common to me.

  • “My grandpa likes dozing with the TV on.”
  • “The kids are having a little doze on the couch.”

Doze off
– (phrasal verb) To fall into a light sleep.

This is more common than “doze.”

  • “I must have dozed off. Are we already there?”
  • “Even though the lecturer’s quite interesting, there are always students that doze off in class.”

– (verb/noun) To sleep lightly for a short time or to be almost asleep.

This is not that common though.

  • “I found him drowsing with a book in his lap.”

– (informal verb/noun) To sleep lightly for a short time, but especially when not in your own bed.

  • “I usually have a little snooze at my desk during my lunch break.”
  • “The dog is snoozing near the window.”

Forty winks
– (British informal noun) Nap.

There is a popular business here in Australia called, “Forty Winks,” that sells beds and mattresses. Otherwise, this is not a term I hear used that often.

  • “She’s going to have forty winks after a long day.”

Get/Put your head down
– (informal British idiom) To sleep.

However, I think this is usually used to refer to a nap.

  • “If you put your head down for a bit, you’ll have more energy for the rest of the day.”

Lie down
– (British phrasal verb) To move into a position in which your body is flat, usually to sleep or rest.

To me, this implies rest rather than sleep or a nap.

  • “Why don’t you go upstairs to lie down?”

– (informal British noun) A short rest, usually on a bed.

  • “He said he didn’t feel well and went to have a lie-down.

Synonyms of FALL ASLEEP

Drift off
– (phrasal verb) To gradually start to sleep.

  • “I think I ate too much for lunch. I was drifting off in the middle of the meeting.”

Drop off
– (phrasal verb) To begin to sleep.

However, this is not that common.

  • “He must’ve dropped off during the movie because he asked me what happened afterwards.”

Nod off
– (phrasal verb) To fall asleep, briefly or unintentionally.

  • “I’ve been so busy lately, I sometimes nod off at the dinner table.”

Conk out
– (phrasal verb) To go to sleep very quickly or it can also mean to suddenly become unconscious. 

Usually this implies exhaustion or a lack of energy.

  • “He conked out on the sofa last night when he came back from the pub.”

Go out like a light
– (informal expression) To go to sleep very quickly.

  • “He went out like a light as soon as his head touched the pillow.”

Crash out
– (phrasal verb) To go to sleep very quickly because you are very tired. 

However, this is not that common.

  • “The kids crashed out in front of the TV.”

– (informal verb) To sleep at someone else’s night for the night, especially when it is not planned.

  • “Feel free to crash at my place if you have nowhere else to go.”

Pass out
– (phrasal verb) To become unconscious for a short time when one is ill, badly hurt or drunk.

Pass out
– (informal phrasal verb) To sleep very quickly because of tiredness. 

This is more common than “crash out.”

  • “We’ve only just got home and she’s already passed out on the sofa.”

Sack out
– (informal American phrasal verb) To go to bed or go to sleep. 

Honestly speaking, I am not familiar with this one.

  • “I’m going to sack out after the show.”

Describing sleep

Light sleep
– (term) Asleep but can be easily woken.

Light sleeper
– (noun) Someone who is easily woken up by noise, etc.

Deep sleep
– (term) Asleep and not easily woken.

Heavy sleeper
– (noun) Someone who is not easily woken up by noise, etc.

In conversational English, “light sleep” is not as common as the others.

  • “Shh! She’s a light sleeper so you have to be quiet.”
  • “She fell into a deep sleep and started dreaming about visiting Disneyland.”

You can use a variety of different adjectives and adverbs to describe the quality of your sleep. There are plenty of words you can use, these are just some common ones.

– (adjective) Satisfactory or pleasant.

– (informal adjective) Very good.

– (informal adjective) Extremely good.

  • “Did you have a good sleep last night?”
  • “How was your sleep?”
    • “It was really good!”

If you want to say that you had bad sleep for one night, we would use positive adjectives in negative sentences.

  • “How was your sleep?”
    • “It wasn’t great. I think I had too much coffee yesterday.”

When it comes to using negative adjectives to describe quality of sleep, these are usually used when describing ongoing problems with sleep as possible health concerns. For this reason, it is more common to see these adjectives used in more formal, health-related articles.

– (adjective) Not good, disappointing or unpleasant.

– (adjective) Not good, being of a very low quality or standard.

– (adjective) Where the normal pattern or functioning is disrupted or interrupted.

– (adjective) Broken, discontinued or hindered.

  • Poor sleep quality may negatively affect your performance levels at work or at school.”
  • “A common cause of disturbed sleep is stress related to work or finances.”

– (adverb) In a good way, to a high or satisfactory standard.

  • “Did you sleep well?”
    • “No, I didn’t sleep very well actually.

– (adverb) In a quiet and calm way.

– (adverb) Deeply.

  • “I’ve always slept soundly, even if the bed is not that comfortable.”
  • “After a feed, the baby finally slept peacefully through the night.”

– (adverb) In a way that is unacceptable or not of good quality.

– (adverb) Only just or almost not.

  • “I always sleep badly because I’m such a light sleeper.”
  • “We’ve hardly slept since the birth of our baby.”

Sleep like a log/baby
– (informal expression) To sleep very well.

  • “My husband sleeps like a log. It’s great because I can watch TV in bed and he won’t be bothered by it.”

Sleep science and health

Sleep medicine
– (noun) A medical specialty that focuses on sleep problems and sleep disorder.

Sleep doctor or Sleep specialist or Somnologist
– (nouns) A doctor that specialises in sleep medicine.

Sleep disorder
(noun) Medical conditions that prevent people sleeping in a normal way and can negatively affect their health.

  • “My GP referred me to a sleep specialist when I told him about my sleeping problems.”
  • “Approximately 60% of Australians have reported symptoms of sleep disorders.”

Sleep study
– (noun) An overnight diagnostic test that allows doctors to monitor you while you sleep – to see what is happening in your brain and body and diagnose sleep disorders.

Sleep clinic
– (noun) A laboratory where sleep studies are conducted.

  • “My doctor booked me in to spend a night at the sleep clinic for a sleep study.”

Circadian rhythm
– (term) A 24-hour cycle that is part of the body’s natural and internal processes that regulates sleep and wakefulness with day and night.

Sleep cycle
– (noun) A regularly occurring pattern of brain waves which occur while we sleep that typically lasts around ninety minutes to two hours.

– (noun) Abbreviation of “rapid eye movement.” During REM sleep, the eyes move around rapidly in a range of directions and dreams typically occur during this time.

(noun) Rapid eye moment does not occur during this period.

  • “A sleep cycle starts with non-REM sleep first before reaching REM sleep, and then the cycle starts all over again.”

Sleep debt/deficit
– (term) The cumulative effect of not getting enough sleep, which may lead to mental or physical fatigue.

Sleep deprivation
– (term) A state caused by consistent inadequate quantity or quality of sleep.

– (noun) The condition of not being able to sleep.

  • “Catching up on sleep on the weekends unfortunately doesn’t eliminate sleep debt.”
  • “Possible side effects of this medication are sleeplessness and restlessness.”

Sleep apnoea
– (noun) A medical condition where someone stops breathing for a short time while sleeping. [“Apnea” is the American spelling.]

  • “Home remedies for sleep apnoea include weight loss, yoga, sleeping on your side, cutting back on alcohol, and using a humidifier.”

– (noun) The condition of not being able to sleep over a period of time.

– (noun) Someone who often finds it different to sleep.

  • “I’ve been suffering from insomnia since I moved away from home.”

– (noun) A medical condition that makes you fall asleep suddenly and unexpectedly.

  • “Did you know that horses can have narcolepsy?”

– (noun) To get out of bed and walk around while still sleeping.

– (noun) Someone who sleepwalks.

  • “I heard you’re not supposed to wake people when they’re sleepwalking.”

Night/Sleep terrors
– (noun) Episodes of screaming, intense fear and flailing while still asleep.

  • “He used to have night terrors when he was a child.”

Other related vocabulary

– (verb) To spend the winter sleeping or in a dormant state.

Hibernation (noun).

This is usually applied to animals but is occasionally applied to humans for academic and research purposes.

  • “Researchers have been studying how to induce hibernation in humans for deep space travel.”

Lie in
– (British phrasal verb) To stay in bed later than usual in the morning.

Sleep in
– (informal phrasal verb) To stay in bed later than usual in the morning.

To me, “sleep in” is more common.

  • “I always look forward to sleeping in on the weekends.”

– (verb) To sleep longer or later than intended.

  • “He would set three alarms so that he wouldn’t oversleep. It hasn’t always worked though.”

Put somebody down
– (phrasal verb) To lay a baby down to sleep.

  • “Give me a minute. I’m going to put the baby down.”

Tuck somebody in
– (phrasal verb) To make someone comfortable in bed, especially a child, by arranging the covers around them.

  • “It’s your turn to tuck her in tonight.”

Sleep over
– (verb) To sleep in someone else’s home for the night.

– (noun) Has the same meaning but can also mean a party where children or young people spend night at a friend’s house.

  • “My nephew sleeps over when his father has a late shift.”
  • “My neighbours are organising a sleepover for Wally’s birthday and invited our son.”

Sleep through something
– (phrasal verb) To sleep without being awakened, usually by loud noise or activity.

  • “She slept through the thunderstorm last night.”

– (adjective) Tired and wanting to sleep.

– (informal noun) Term to call a person, usually a child, who is tired and looks like they want to sleep.

  • “Come on sleepyhead. Let’s tuck you into bed.”

Sleep something off
– (phrasal verb) To recover from something by going to sleep.

  • “If the headache is not too bad, you should sleep it off instead of taking an aspirin.”

Sleep tight
– (interjection) Said to someone who is going to bed. It means that you hope they sleep well.

See also: Phrasal verbs with SLEEP

Original posts: 30 March 2021