mid-14c., from Medieval Latin embryo, from Greek embryon "a young one," in Homer, "young animal," later, "fruit of the womb," literally "that which grows," from en "in" (see en- (2)) + bryein "to swell, be full."
embryo em·bry·o (ěm'brē-ō')
n. pl. em·bry·os
An organism in its early stages of development, especially before it has reached a distinctively recognizable form.
An organism at any time before full development, birth, or hatching.
The fertilized egg of a vertebrate animal following cleavage.
In humans, the prefetal product of conception from implantation through the eighth week of development.
embryo- or embry-
pref.
Embryo: embryogenesis.
A developing plant or animal. A plant embryo is an undeveloped plant inside a seed. An animal embryo is the animal as it develops from the single cell of the zygote until birth. Among humans and most other mammals, the embryo is carried in the mother's womb.
Note: The term is occasionally used to denote a new or developing idea or project: “The idea for the complete theory was already present in his work, in embryo form, in 1950.”