ec.to.derm
n.（名词）The outermost of the three primary germ layers of an embryo, from which the epidermis, nervous tissue, and, in vertebrates, sense organs develop.外胚层：胚胎最初三层胚层中的最外一层，由此发育成为表皮、神经组织和脊椎动物的感觉器官The outer layer of a diploblastic animal, such as a jellyfish.外层：双胚层动物的外层，如海蜇
【引伸】
ec.toder.mal 或
ec.toder.mic
adj.（形容词）
