Main Entry: em·bryo

Pronunciation: \ˈem-brē-ˌō\

Function: noun

Inflected Form(s): plural em·bry·os

1 archaic : a vertebrate at any stage of development prior to birth or hatching
2 : an animal in the early stages of growth and differentiation that are characterized by cleavage, the laying down of fundamental tissues, and the formation of primitive organs and organ systems ; especially : the developing human individual from the time of implantation to the end of the eighth week after conception—compare fetus