EMBRYO

noun (plural ~s) Etymology: Medieval Latin ~n-, ~, from Greek ~n, from en- + bryein to swell; akin to Greek bryon catkin Date: 1548 1. a vertebrate at any stage of development prior to birth or hatching, an animal in the early stages of growth and differentiation that are characterized by cleavage, the laying down of fundamental tissues, and the formation of primitive organs and organ systems, the young sporophyte of a seed plant usually comprising a rudimentary plant with plumule, radicle, and cotyledons, 3. something as yet undeveloped, a beginning or undeveloped state of something