The Collaborative International Dictionary
Pterygiums
Pterygium \Pte*ryg"i*um\, n.; pl. E. Pterygiums, L. Pterygia. [NL., fr. Gr. ?, properly a dim, akin to ? a feather.] (Med.) A superficial growth of vascular tissue radiating in a fanlike manner from the cornea over the surface of the eye.
Wiktionary
pterygiums
n. (plural of pterygium English)