[ toh-sis ]
/ ˈtoʊ sɪs /

noun Pathology.

a drooping of the upper eyelid.
prolapse or drooping of any organ.

Origin of ptosis

1735–45; < New Latin < Greek ptṓsis a falling


pto·tic [toh-tik] /ˈtoʊ tɪk/, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for ptosis

British Dictionary definitions for ptosis

/ (ˈtəʊsɪs) /

noun plural ptoses (ˈtəʊsiːz)

prolapse or drooping of a part, esp the eyelid

Derived forms of ptosis

ptotic (ˈtɒtɪk), adjective

Word Origin for ptosis

C18: from Greek: a falling
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

Medicine definitions for ptosis

[ tōsĭs ]

n. 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® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.