ˈtōsə̇s noun
( plural pto·ses -ōˌsēz)
Etymology: New Latin, from Greek ptōsis fall, falling, from piptein to fall
: a sagging or prolapse of an organ or part (as one of the abdominal viscera)
renal ptosis
specifically : drooping of the upper eyelid (as from paralysis of the oculomotor nerve)