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hypersomnia

[hahy-per-som-nee-uh]
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noun Pathology.
  1. a tendency to sleep excessively.
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Origin of hypersomnia

First recorded in 1875–80; hyper- + (in)somnia
Related formshy·per·som·ni·ac, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

hypersomniac in Medicine

hypersomnia

(hī′pər-sŏmnē-ə)
n.
  1. A condition in which one sleeps for an excessively long time but is normal in the waking intervals.
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The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.