The transparent convex anterior portion of the outer fibrous coat of the eyeball that covers the iris and the pupil and is continuous with the sclera.
[Medieval Latin cornea (tēla), horny (tissue), from Latin corneus, horny, from cornū, horn; see ker-1 in the Appendix of Indo-European roots.]
corne·al (-əl) adj.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.