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

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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 The benefits of an early nap can wear off too early in the day, leading to afternoon sleepiness. — Heidi Moawad, Verywell Health, 21 July 2026 Melatonin the hormone released at night that triggers sleepiness also declines with age, and perimenopause brings a significant drop that makes sound sleep harder to come by. — Hanna Wickes, Fort Worth Star-Telegram, 17 July 2026 Gamma-wave strength rose across brain regions during therapy, and sleepiness was the most common side effect. — Samantha Agate, Sacbee.com, 13 July 2026 The clinical data demonstrated significant improvements in wakefulness and reductions in excessive daytime sleepiness at week eight, outperforming the placebo with a generally favorable safety profile. — Sasirekha Subramanian, Forbes.com, 29 June 2026 In the study, people who reported excessive daytime sleepiness had higher odds of hypertension than those who didn’t. — Zoe Cunniffe, Health, 18 June 2026 Researchers also observed improvements in sleep maintenance and reductions in daytime fatigue, anxiety, depression symptoms and daytime sleepiness. — Samantha Agate, Kansas City Star, 7 May 2026 Researchers measured insomnia severity using the Insomnia Severity Index, along with sleep maintenance, daytime sleepiness, fatigue, anxiety and depression symptoms. — Samantha Agate, Charlotte Observer, 7 May 2026 Mention any daytime symptoms, such as excessive sleepiness or headaches, and any nighttime symptoms, such as frequent urination, waking up short of breath, snoring or insomnia. — Erika Yamazaki, The Conversation, 6 May 2026
Recent Examples of Synonyms for sleepiness
  1. drowsiness
  2. fatigue
  3. sleeping
  4. somnolence
Noun
  • Some symptoms of diphenhydramine poisoning include drowsiness, agitation, fast heart rate, nausea, vomiting, hallucinations, seizures, dangerous heart rhythm and loss of consciousness.
    — Angelica Stabile, FOXNews.com, 19 June 2026
  • It is also known to cause side effects, including drowsiness, sedation and dizziness.
    — Mary Walrath-Holdridge, USA Today, 12 June 2026
Definition of drowsiness
Noun
  • The fever and the less intense strain often presents as a headache, fever, muscle and joint aches, nausea, and fatigue.
    — Mary Ella Hastings July 24, Fort Worth Star-Telegram, 24 July 2026
  • Subscription fatigue is real and only getting worse; according to a 2023 Harvard Business School study, nearly 75% of consumer-facing companies offer some form of subscription service.
    — Bee Wertheimer, PC Magazine, 24 July 2026
Definition of fatigue
Noun
  • At night, that lounge converts over into one of two double beds, the other dropping into sleeping form from the wraparound dining area up front.
    — New Atlas, New Atlas, 23 July 2026
  • The city already refers those found sleeping or camping outside to area services, such as emergency housing, case management and food assistance.
    — Jenna Ebbers, Kansas City Star, 23 July 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
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Cite this Entry

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

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More from Merriam-Webster on sleepiness

Nglish: Translation of sleepiness for Spanish Speakers

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