epiboly
/ɛpɪˈbɒli/ or /epɪˈbɒli/Definitions
1. noun
The process by which an animal’s blastula (a stage in embryonic development) transforms into a gastrula by enveloping the yolk, resulting in the formation of the embryo’s three primary germ layers.
“During the early stages of development, the embryo undergoes epiboly, which is crucial for the proper formation of its germ layers.”