Definition of germinal membrane in US English:

germinal membrane

noun

  • 1Blastoderm (now rare).

  • 2The thin inner layer (endocyst) of the wall of a hydatid cyst, from which its brood capsules and protoscoleces are derived.

Origin

Mid 19th century. Compare German Keimhaut and scientific Latin membrana germinativa (both 1828 or earlier).