Trophoblast

1 definition found

From WordNet (r) 2.0 [wn]:

  trophoblast
       n : the membrane that forms the wall of the blastocyst in early
           development; aids implantation in the uterine wall;
           "after implantation of the blastocyst in the uterine wall
           the trophoblast divides into two layers, the chorion and
           the placenta"