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 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 Shift Work Sleep Disorder, or SWSD, is the clinical name for the persistent insomnia or excessive sleepiness that lasts more than three months and is tied directly to a person’s work schedule. — Allison Palmer, Fort Worth Star-Telegram, 16 May 2026 However, sleepiness returns when the caffeine wears off. — Ashley Olivine, Verywell Health, 11 May 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
  • If testosterone levels are too low, at any age, this can lead to muscle and bone weakness, fatigue, and decline in libido.
    — Nina Shapiro, Forbes.com, 18 July 2026
  • Warning signs worth flagging to a doctor include loud snoring, gasping for air during sleep, severe daytime fatigue, persistent low mood, rapid heart rate and unexplained weight changes.
    — Hanna Wickes, Fort Worth Star-Telegram, 17 July 2026
Definition of fatigue
Noun
  • Sleep systems Choosing the right sleeping foundation is essential.
    — Clay Abney, Travel + Leisure, 16 July 2026
  • The seat-block option comes four months after United unveiled a new Relax Row option, a row of three economy seats with individually adjustable leg rests that fold up at a 90-degree angle to create a lie-flat sleeping area.
    — Mason Leib, ABC News, 14 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

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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 21 Jul. 2026.

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More from Merriam-Webster on sleepiness

Nglish: Translation of sleepiness for Spanish Speakers

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