|—n , pl -lies|
|embryol a process that occurs during gastrulation in vertebrates, in which cells on one side of the blastula grow over and surround the remaining cells and yolk and eventually form the ectoderm|
|[C19: from Greek epibolē a laying on, from epiballein to throw on, from |
epiboly e·pib·o·ly (ĭ-pĭb'ə-lē)
The growth of a rapidly dividing group of cells around a more slowly dividing group of cells, as in the formation of a gastrula.