sleepiness

noun

Definition of sleepinessnext
as in drowsiness
the quality or state of desiring or needing sleep the truck driver keeps a thermos of coffee with him to stave off sleepiness

Synonyms & Similar Words

Relevance

Antonyms & Near Antonyms

Example Sentences

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Recent Examples of sleepiness Advertisement Tell your doctor about the pauses, gasping, and any daytime sleepiness. — Angela Haupt, Time, 16 Oct. 2026 Hufanga explained that the drink’s effects can act like alcohol, inducing muscle relaxation, sleepiness, and feelings of well-being. — Sam Jane, Denver Post, 29 Sep. 2026 Other common sleep issues that don’t affect the airways include movement disorders that cause nighttime restlessness or narcolepsy, a neurological disorder that affects the body’s sleep-wake cycles and causes excessive sleepiness. — Samantha Agate, Sacbee.com, 24 Sep. 2026 In young children, THC intoxication can cause profound sleepiness, confusion, impaired coordination, vomiting and changes in heart rate. — Katia Hetter, CNN Money, 10 Sep. 2026 To sleep, no more Two scientists who identified the role that a key neuropeptide plays in the uncontrollable sleepiness of narcolepsy were one of three recipients of the prestigious Lasker Awards, announced Thursday. — O. Rose Broderick, STAT, 10 Sep. 2026 Consuming the oil or leaves can cause vomiting, dizziness, sleepiness, and muscle weakness. — Sarah Bence, Verywell Health, 25 Aug. 2026 Takeda is testing orexin-targeting drugs for sleep apnea and chronic daytime sleepiness. — Harriet Marsden, TheWeek, 20 Aug. 2026 Adherence is often low, and untreated sleep apnea can worsen hypertension, atrial fibrillation and the daytime sleepiness. — Jesse M. Pines, Forbes.com, 10 Aug. 2026
Recent Examples of Synonyms for sleepiness
  1. drowsiness
  2. fatigue
  3. sleeping
  4. somnolence
Noun
  • The Cleveland Clinic notes that as bedtime approaches, the body begins lowering its core temperature as part of the circadian rhythm that signals drowsiness.
    — Hanna Wickes, Fort Worth Star-Telegram, 22 Oct. 2026
  • In addition, both magnesium and L-theanine do not cause daytime drowsiness, so they can be taken at any time.
    — Emmanuella Ogbonna, HEALTH, 2 Oct. 2026
Definition of drowsiness
Noun
  • Indeed, even after modern jeans were invented in the late 19th century, denim continued to be used to make such apparel as work jackets, prison uniforms, naval fatigues, and jumpsuits.
    — Britannica Editors, Encyclopedia Britannica, 23 Oct. 2026
  • But many live with fatigue, weakness, brain fog and other symptoms for months or years before a deficiency is caught.
    — Amanda Schupak, CNN Money, 23 Oct. 2026
Definition of fatigue
Noun
  • In November 2005, church volunteer Scott Preston Moore entered sleeping quarters at night and inappropriately touched two teenage boys.
    — Jack Harvel, Kansas City Star, 20 Oct. 2026
  • Downstairs is a spacious sleeping area that could also work as a gym or home office and benefits from an enormous skylight equipped with automatic blackout shades.
    — Matthew Sedacca, Curbed, 19 Oct. 2026
Definition of sleeping
Noun
  • From there, the story builds on the uncertainty, rocking the somnolence of a small town in the province of Badajoz, and forcing a community to choose between disbelief and the need to prove what can’t be seen.
    — Emiliano De Pablos, Variety, 9 Feb. 2026
  • The people went to the emergency department with tachycardia, confusion, anxiety or somnolence, and nausea after eating gummy candies labeled as containing Amanita muscaria mushrooms.
    — Beth Mole, Ars Technica, 19 July 2024
Definition of somnolence

Browse Nearby Words

sleep in
sleepiness
sleeping
See all Nearby Words

Cite this Entry

“Sleepiness.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/sleepiness. Accessed 28 Oct. 2026.

Copy Citation
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Last Updated: - Updated example sentences

More from Merriam-Webster

Word of the Day

Listen to the pronunciation of grotesque

See Definitions and Examples »

Popular in Grammar & Usage

See More

How to Use 'Who' vs. 'Whom'

Merriam-Webster’s Great Big List of Words You Love to Hate

'Affect' vs. 'Effect'

'A' or 'an'? What about before 'h'? An Indefinite Article Guide

Why is '-ed' sometimes pronounced at the end of a word?
See More

Popular in Wordplay

See More

The Longest Long Words List

9 Words That Sound Like Insults But Aren't

12 Lovely and Unusual Words for the Natural World

Why do we 'bury the lede?'

'Za' and 9 Other Words to Help You Win at SCRABBLE
See More

Popular

See More

How to Use 'Who' vs. 'Whom'

The Longest Long Words List

9 Words That Sound Like Insults But Aren't
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
The Missing Letter A daily crossword with a twist
different halloween monsters in silhouette
A Monstrous Vocab Quiz Words That Go Bump in the Night
See All