PTOSIS Meaning of PTOSIS in English — ptotic /toh"tik/ , adj./toh"sis/ , n. Pathol.1. a drooping of the upper eyelid. 2. prolapse or drooping of any organ. [ 1735-45; ptósis a falling ] Random House Webster's Unabridged English dictionary. Полный английский словарь Вебстер - Random House . 2012