1. Anatomy The small, circular, optically insensitive region in the retina where fibers of the optic nerve emerge from the eyeball. It has no rods or cones. Also called optic disk.
2. An area that one cannot see because of an obstruction or because of insufficient range of view.
3. An area where radio reception is weak or nonexistent.
4. A subject regarding which one is unable to perceive the truth or judge objectively: His niece is his blind spot; in his eyes, she can do no wrong.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 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.