n.
Pronunciation: ' gas-tr ə -l ə
Function: noun
Inflected Form: plural -las or -lae \ - ˌ l ē , - ˌ l ī \
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 \ -l ə r \ adjective