Crossword clue: the outermost membranous sac enclosing the embryo in higher vertebrates (reptiles, birds and mammals)

The most common answer is chorion (7 letters).

1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

Possible answers

chorion 7 letters wn-def

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