extraembryonic
Adjective
Meaning
extraembryonic (not comparable)
(medicine) Inside the womb, but outside the embryo.
Examples
But embryos fed by a placenta or extraembryonic yolk supply can grow very fast, and changes to relative growth rate between parts in these organisms help to produce the final overall anatomy.
After that, the epiblast and the hypoblast establish contact with the extraembryonic mesoderm until they cover the yolk sac and amnion.