n.
Pronunciation: ' tr ō -f ə - ˌ blast
Function: noun
Etymology: International Scientific Vocabulary
Date: 1889
: the outer layer of the mammalian blastocyst that supplies nutrition to the embryo and facilitates implantation
– tro · pho · blas · tic \ ˌ tr ō -f ə - ' blas-tik \ adjective