ptosis

ptosis definition - medical

pto·sis (tōˈsĭs)

noun pl. pto·ses (-sēz)
Abnormal lowering or drooping of an organ or part, especially a drooping of the upper eyelid caused by muscle weakness or paralysis.

The American Heritage® Medical Dictionary Copyright © 2009 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

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