Search proptosis proptosis /proptō″sis/ [L, pro + ptosis, falling] , a bulging, protrusion, or forward displacement of a body organ or area. Proptosis of the right eye (Kanski and Nischal, 1999) Tweet Telegram VK Random Words insensible sulfiting agents nirvanic state streptokinase (SK) popliteal pulse mitochondrion National Institute on Drug Abuse (NIDA) -pubic exercise electrocardiogram (ECG)