epibolic

noun, plural e·pib·o·lies. Embryology.

1. the movement and spreading out of cells into sheets of tissue that overlie or surround other groups of cells, especially as in the formation of certain gastrulas.

noun plural -lies

1. 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

n.

1. The growth of a rapidly dividing group of cells around a more slowly dividing group of cells, as in the formation of a gastrula.