Lewis Short
ptĕrygĭum (noun N) = πτερύγιον: .
* A film that grows over the eye, a pearl, web, or haw, Cels. 7, 7, 4; Plin. 32, 7, 24. § 72; 34, 10, 23, § 105.
* A growth of flesh over the nails, Plin. 24, 4, 5, § 9; 26, 5, 14, § 26; 27, 4, 5, § 20; 30, 12, 37, § 111; cf. Cels. 6, 19, 1.
* A cloudy spot in the beryl, Plin. 37, 5, 20, § 79.
Charlton T. Lewis, Charles Short, A Latin Dictionary