When you wake up on the wrong side of the bed, sleep like a bug in a rug, or can't sleep a wink, do you know what you're talking about? Sleep, of course!

All living beings need sleep to survive, so it's perfectly natural that we all talk about sleep. In fact, our language incorporates sleep in a lot of fun and interesting ways. Let's begin our study of sleep language by finding out some of the old mythology that gave us some interesting sleep words.

Hypnos: Greek God of Sleep

Hypnos might be a minor deity in Greek mythology, but he sure left a lasting legacy of sleep language. This Greek god helped people sleep soundly. He came from Nyx, the goddess of night, and Erebus, the god of darkness, and his twin brother Thanatos helped people die peacefully.

With this lineage, it is only appropriate that Hypnos' four children would be the influencers of dreams, namely Morpheus, Phobetor, Phantasus, and Ikelos. Do any of these words sound vaguely familiar? They should! The following words are all derived from Hypnos and the names of his family members:

• hypnosis
• insomnia
• euthanasia
• phobia
• morphine

The Etymology of Sleep

Etymology means the study of the origin of words. The English word "sleep" originates from a Germanic language. The Gothic word "sleps" is related to the modern German word "schlaf" and the Dutch word "slaap."

But let's not stop with English. European Romance languages (such as French and Italian) take their words for sleep from a Latin word, "somnus." This word should strike a bell for English speakers as well. Our English words "somnolent," "insomnia," and "somnambulist" also come from "somnus." What is a somnambulist? A sleepwalker!

Fun Sleep Vocabulary

How extensive is your sleep vocabulary? Take this 5-question multiple choice quiz to find out!

1. Soporific means:
2. tending to induce drowsiness or sleep
3. an exhilarating feeling one has while dreaming
4. a calming aroma that wafts through the air

1. Narcolepsy means:
2. self-centeredness
3. the ability to control your dreams
4. a condition in which a person easily falls asleep in relaxing surroundings

1. Quietus means:
2. a chamber inside a monastery
3. a release from life
4. a short nap

1. Torpor means:
2. a state of physical or mental inactivity
3. a tool designed to hypnotize a person to sleep
4. a dreary time of day

1. Quiescent means:
2. a quiet place to talk
3. the ability to day-dream
4. at rest

How did you do? The answers are:

1a, 2c, 3b, 4a, 5c

Sleep-Related Medical Terms

The world of medicine contains a whole slew of sleep-related words, probably because so many things go awry in the human body when your sleeping habits are off-course. Check out these sleep-related medical terms.

• Circadian rhythms: These rhythms are the internal clock that tells our bodies when to sleep and how long to sleep.
• Sleep apnea: This is a sleeping disorder in which a person's breathing is interrupted.
• Parasomnias: This is a collective term for strange behaviors during sleep. Sleepwalking is an example of parasomnia.
• Sleep paralysis: This occurs when a person temporarily cannot move or speak while falling asleep or waking up.
• Polysomnography: This is a test a doctor might give you to evaluate for sleep disorders, such as sleep apnea. The test records amount of sleep, breathing patterns, heart rhythms, movements of arms and legs, etc.
• Chronotherapy: This type of therapy adjusts a patient's bedtime, usually to fix an out-of-sync sleep-wake pattern.
• Motor Atonia: This is a condition in which a person has no muscle activity during sleep.

Sleep Idioms

Not all sleep terms are challenging to understand. Here are some sleep idioms that you might hear on an everyday basis. Which ones do you use?

• catnap
• catch some Zzzs
• hit the sack
• turn in
• out like a light
• power nap
• wake up on the wrong side of the bed
• grab a little shut-eye
• night owl
• get up at the crack of dawn
• early bird
• tuck your children in
• rise and shine
• sleep on it
• burn the candle at both ends
• sleep like a log
• forty winks
• sleep tight
• don't let the bedbugs bite
• beauty sleep
• drift off to sleep
• sleep with one eye open
• sleeping on the job

Literary Sleep

It's only natural that rest would come up in popular literature. After all, authors often write what they know, and everyone knows about sleep! Here are some quotes about sleep from great works of literature.

We rose up betimes, for sleep weighs lightly on the hopeful as well as on the anxious.

— from The Swiss Family Robinson by Johann D. Wyss

O sleep, O gentle sleep, Nature's soft nurse, how have I frightened thee, that thou no more will weigh my eyelids down, and steep my senses in forgetfulness?

— from Henry IV, Part Two by William Shakespeare

How blessed are some people, whose lives have no fears, no dreads, to whom sleep is a blessing that comes nightly, and brings nothing but sweet dreams.

— from Dracula by Bram Stoker

The sigh of all the seas breaking in measure round the isles soothed them; the night wrapped them; nothing broke their sleep, until, the birds beginning and the dawn weaving their thin voices in to its whiteness.

— from To the Lighthouse by Virginia Woolf

Come Sleep, O Sleep, the certain knot of peace,/ The baiting place of wit, the balm of woe,/ The poor man's wealth, the prisoner's release,/ The indifferent judge between high and low.

— from "Sonnet 39" by Sir Philip Sidney

Lullabies and Mattresses

Of course, the most logical language to use at bedtime is a lullaby. Did you have a favorite lullaby when you were a child? Do you sing lullabies to your children? Maybe you hum a certain song to help yourself drift off to sleep. From Brahms Lullaby to Hush, Little Baby, these little songs have a way of making our eyelids heavy as we sink deeper under the covers.