trophectoderm
noun
troph·ec·to·derm
| \ ˌtrōf-ˈek-tə-ˌdərm
\
\
Medical Definition of trophectoderm
: trophoblast
especially
: the outer layer of the mammalian blastocyst after differentiation of the ectoderm, mesoderm, and endoderm when the outer layer is continuous with the ectoderm of the embryo