See hybrid vigor.
[Late Greek heterōsis, alteration, alteration of Greek heteroiōsis, from heteroioun, to alter, from heteroios, different in kind, from heteros, other; see HETERO-.]
het′er·otic (-rŏtĭk) adj.
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.