noun
blastocyst; blastodermic vesicle
A biological term for the early mammalian embryo stage, used in developmental biology and reproductive medicine.
胚盤胞は受精後約5日で形成される。
The blastocyst forms about five days after fertilization.
A modern scientific compound: 胚 (はい, embryo) + 盤 (ばん, disc) + 胞 (ほう, sac/cyst), reflecting the structure of the blastocyst.