1. The reappearance of a characteristic in an organism after several generations of absence.
2. An individual or a part that exhibits atavism. Also called throwback.
3. The return of a trait or recurrence of previous behavior after a period of absence.
[French atavisme, from Latin atavus, ancestor : atta, father + avus, grandfather; see awo- in the Appendix of Indo-European roots.]
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.