proptosis
noun
prop·to·sis präp-ˈtō-səs 
prō-ˈtō-
prō-ˈtō- : forward projection or displacement especially of the eyeball
Example Sentences
Recent Examples on the Web Bulging or protruding eyes (proptosis or exophthalmos) can be a sign of Graves disease, a disorder causing overactivity of the thyroid gland (hyperthyroidism). 
Claire Gillespie, SELF, 19 Oct. 2017
Claire Gillespie, SELF, 19 Oct. 2017 Word History
Etymology
New Latin, from Late Latin, falling forward, from Greek proptōsis, from propiptein to fall forward, from pro- forward + piptein to fall — more at pro-, feather
First Known Use
1676, in the meaning defined above
Medical Definition
proptosis
noun
pro·pto·sis (ˈ)prō-ˈtō-səs präp-ˈtō-
präp-ˈtō- plural proptoses -ˌsēz
: forward projection or displacement especially of the eyeball