n. The fecundated germ of an animal in its earlier stages of development, and before it has assumed the distinctive form and structure of the parent; a germ; a rudiment; in a more extended sense, a rudimentary animal during its whole antenatal existance.n. In botany, the rudimentary plant contained in the seed, the result of the action of pollen upon the ovule.n. The beginning or first state of anything, while yet in a rude and undeveloped condition; the condition of anything which has been conceived but is not yet developed or executed; rudimentary state: chiefly in the phrase in embryo.n. Synonyms Fetus, Germ, Rudiment. The first of these words is mainly applied to the embryos of viviparous vertebrates in the later stages of their development, when they are more subject to observation. Germ means especially the seed or fecundated ovum, and scarcely extends beyond the early stages of an embryo. Rudiment is simply the specific application of a more general term to a germ or to the early, crude, or ‘rude’ stages of an embryo.Being in the first or rudimentary stage of growth or development; incipient; embryonic: as, an embryo flower.