Main Entry: gas·tru·la

Pronunciation: \ˈgas-trə-lə\

Function: noun

Inflected Form(s): plural gas·tru·las or gas·tru·lae \-ˌlē, -ˌlī\

Etymology: New Latin, from gastr-

Date: 1876

: an early metazoan embryo in which the ectoderm, mesoderm, and endoderm are established either by invagination of the blastula (as in fish and amphibians) to form a multilayered cellular cup with a blastopore opening into the archenteron or by differentiation of the blastodisc (as in reptiles, birds, and mammals) and inward cellular migration — compare blastula, morula

— gas·tru·lar \-lər\ adjective