The Collaborative International Dictionary of English v.0.48:
Embryonal \Em"bry*o*nal\, a. (Biol.) Pertaining to an embryo, or the initial state of any organ; embryonic. [1913 Webster]WordNet (r) 3.0 (2006):
embryonal adj 1: of an organism prior to birth or hatching; "in the embryonic stage"; "embryologic development" [syn: embryonic, embryologic, embryonal]