• synonyms


[ mahy-uh s-thee-nee-uh ]
/ ˌmaɪ əsˈθi ni ə /

noun Pathology.

muscle weakness.

Nearby words

myalgic encephalopathy, myalism, myall, myanmar, myasis, myasthenia, myasthenia gravis, myasthenic, myasthenic facies, myatonia, myatonia congenita

Origin of myasthenia

First recorded in 1855–60; my- + asthenia
Related formsmy·as·then·ic [mahy-uh s-then-ik] /ˌmaɪ əsˈθɛn ɪk/, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for myasthenia

  • He compares it to certain forms of cardiac dilatation—both expressions of myasthenia.

    A System of Practical Medicine By American Authors, Vol. II|Various

British Dictionary definitions for myasthenia


/ (ˌmaɪəsˈθiːnɪə) /


any muscular weakness
Derived Formsmyasthenic (ˌmaɪəsˈθɛnɪk), adjective

Word Origin for myasthenia

C19: from myo- + asthenia
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for myasthenia



"muscular weakness," 1856, medical Latin; see myo- + asthenia.

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for myasthenia


[ mī′əs-thēnē-ə ]


Abnormal muscular weakness or fatigue.
Myasthenia gravis.
Related formsmy′as•thenic (-thĕnĭk) adj.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.