What is "epiboly"

Epiboly \E*pib"o*ly\, n. [Cf. Gr. ? a throwing upon.] (Biol.) Epibolic invagination. See under Invagination.

n. (context embryology English) The expansion of one cell sheet over other cells, as takes place during gastrulation or secondary intention wound healing.

Epiboly is a cell movement that occurs in the early embryo, at the same time as gastrulation. It is one of many movements in the early embryo that allow for dramatic physical restructuring (see morphogenesis). The movement is generally characterized as being a thinning and spreading of cell layers. Epiboly has been most extensively studied in zebrafish as their development allows for an easy visualization of the process.