The Collaborative International Dictionary of English v.0.48:

Morula \Mor"u*la\, n.; pl. Morulae. [NL., dim. of L. morum a
   mulberry.] (Biol.)
   The sphere or globular mass of cells (blastomeres), formed by
   the clevage of the ovum or egg in the first stages of its
   development; -- called also mulberry mass, segmentation
   sphere, and blastosphere. See Segmentation.
   [1913 Webster]

WordNet (r) 3.0 (2006):

morula
    n 1: a solid mass of blastomeres that forms when the zygote
         splits; develops into the blastula