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hypersomnia

American  
[hahy-per-som-nee-uh] / ˌhaɪ pərˈsɒm ni ə /

noun

Pathology.
  1. a tendency to sleep excessively.


Other Word Forms

  • hypersomniac noun

Etymology

Origin of hypersomnia

First recorded in 1875–80; hyper- + (in)somnia

Vocabulary lists containing hypersomnia

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

It’s acquiring Centessa Pharmaceuticals, which is working on orexin receptor 2 agonists for conditions like narcolepsy and idiopathic hypersomnia — forms of daytime sleepiness.

From MarketWatch • Mar. 31, 2026

Its first-generation candidate, ORX750, is aimed at treating three types of severe narcolepsy—type I, type II, and idiopathic hypersomnia.

From Barron's • Sep. 26, 2025

Symptoms of idiopathic hypersomnia include not only being very sleepy during the day, but also sleeping excessive amounts of time, having difficulty waking up, and waking up disoriented.

From Science Daily • Dec. 13, 2023

These results align, she said, with a 2015 study of a few dozen hypersomnia patients from her clinic who were helped by Xyrem.

From Seattle Times • Aug. 12, 2021

I generally drink from half to three-quarters of a cup of black coffee, or nearly black, every morning at from eleven to five minutes past, so as to keep off hypersomnia.

From Moonbeams from the Larger Lunacy by Leacock, Stephen