Chorion

[kɒ:riɒn]

(noun.) the outermost membranous sac enclosing the embryo in higher vertebrates (reptiles, birds and mammals).

Checker: McDonald--From WordNet

(n.) The outer membrane which invests the fetus in the womb; also, the similar membrane investing many ova at certain stages of development.

(n.) The true skin, or cutis.

(n.) The outer membrane of seeds of plants.

Typist: Steven

n. the outer fœtal envelope: the external membrane of the seeds of plants:—pl. Chō′ria.—adj. Chō′roid.

Checked by Freda