blastomere

from WordNet (r) 3.0 (2006)

blastomere
    n 1: any cell resulting from cleavage of a fertilized egg

from The Collaborative International Dictionary of English v.0.48

Blastomere \Blas"to*mere\, n. [Gr. blasto`s sprout + -mere.]
   (Biol.)
   One of the segments first formed by the division of the ovum.
   --Balfour.
   [1913 Webster]