The inner or lower layer of the blastoderm; -- called also endoderm, entoderm, and sometimes hypoderm. See Illust. of Blastoderm, Delamination, and Ectoderm.
Gr. hypo - under, beneath; Gr. blastos - germ, bud shoot]. The inner layer of amniote blastoderm. Its cells usually become the endoderm of the extraembryonic membranes.