1. An act, assertion, or belief that unintentionally deviates from what is correct, right, or true.
2. The condition of having incorrect or false knowledge.
3. The act or an instance of deviating from an accepted code of behavior.
4. A mistake.
5. Mathematics The difference between a computed or measured value and a true or theoretically correct value.
6. Abbr. E Baseball A defensive fielding or throwing misplay by a player when a play normally should have resulted in an out or prevented an advance by a base runner.
[Middle English errour, from Old French, from Latin error, from errāre, to err; see ers- in the Appendix of Indo-European roots.]
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.