The Collaborative International Dictionary of English v.0.48:
Embryo \Em"bry*o\, n.; pl. Embryos. [F. embryon, Gr.
'e`mbryon, perh. fr. ? in (akin to L. ? E. in) + ? to be full
of, swell with; perh. akin to E. brew.] (Biol.)
The first rudiments of an organism, whether animal or plant;
(a) The young of an animal in the womb, or more specifically,
before its parts are developed and it becomes a 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."