embryonic disk

[ em-bree-on-ik disk ]

noun

, Embryology.

1. Also called embryonic shield. in the early embryo of mammals, the flattened inner cell mass that arises at the end of the blastocyst stage and from which the embryo begins to differentiate.
2. the blastodisk of yolky eggs.

Word History and Origins

Origin of embryonic disk¹

First recorded in 1935–40