What does "embryo" mean?

Embryo: The first rudiments of an organism, whether animal or plant; as: (a) The young of an animal in the womb, or more specifically, before its parts are developed and it becomes a fetus (see Fetus). (b) The germ of the plant, which is inclosed in the seed and which is developed by germination. In embryo, in an incipient or undeveloped state; in conception, but not yet executed. "The company little suspected what a noble work I had then in embryo." Swift.