Source : Webster's Revised Unabridged Dictionary (1913)

Ectoblast \Ec"to*blast\, n. [Ecto- + Gr. ? bud, germ.] (Biol.)
   (a) The outer layer of the blastoderm; the epiblast; the
       ectoderm.
   (b) The outer envelope of a cell; the cell wall. --Agassiz.

Source : WordNet®

ectoblast
     n : the outer germ layer that develops into skin and nervous
         tissue [syn: {ectoderm}, {exoderm}]