Ectoderm
Pronunciation : Ec"to*derm
Part of Speech : n.
Etymology : [Ecto- + -derm.] (Biol.) (a) The outer layer of the blastoderm; epiblast. (b) The external skin or outer layer of an animal or plant, this being formed in an animal from the epiblast. See Illust. of Blastoderm.
Source : Webster's Unabridged Dictionary, 1913