Webster’s Revised Unabridged Dictionary · 1913
Ectental
Ec·ten′tal (ĕk·tĕn′tal), a. [Gr. ἐκτός outside + ἐντός inside.] (Biol.) Relating to, or connected with, the two primitive germ layers, the ectoderm and ectoderm; as, the "ectental line" or line of juncture of the two layers in the segmentation of the ovum. C. S. Minot.