entomere

Century Dictionary and Cyclopedia

1. n. In embryology, the more granular of the two blastomeres into which the mammalian ovum divides, or a descendant of it in the first stages of development. The entomeres come to form the center of the mass of blastomeres, the other and outer blastomeres being called ectomeres.

Wiktionary

1. n. biology One of the more granular cells, which finally become internal, in many segmenting ova, such as those of mammals.

GNU Webster's 1913

1. n. (Biol.) The more granular cells, which finally become internal, in many segmenting ova, as those of mammals.