a drooping of the upper eyelid.
prolapse or drooping of any organ.
Origin of ptosis
1735–45; < New Latin < Greek ptṓsis a falling
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
noun plural ptoses (ˈtəʊsiːz)
prolapse or drooping of a part, esp the eyelid
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
1743, from Greek ptosis, literally "falling, a fall," also "the case of a noun," nominal derivative of piptein "to fall" (see symptom). In English, especially of the eyelid. Related: Ptotic.
Online Etymology Dictionary, © 2010 Douglas Harper
Relating to or characterized by ptosis.
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.