The growth of a rapidly dividing group of cells around a more slowly dividing group of cells, as in the formation of a gastrula.
[Greek epibolē, a throwing or laying on, from epiballein, to throw on : epi-, epi- + ballein, to throw; see gwelə- in the Appendix of Indo-European roots.]
ep′i·bolic (ĕp′ə-bŏlĭk) 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.