The New Dictionary of Cultural Literacy, Third Edition. 2002.
embryo
(EM-bree-oh) 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 mothers womb.
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.