/ Dictionary / Index E extraembryonic membrane: Meaning and Definition of Find definitions for: ex'traembryon'ic mem'brane Pronunciation: [key] — Embryol. Embryol. any of the tissues, derived from the fertilized egg, that enclose or otherwise contribute to the support of the developing embryo, as the yolk sac, allantois, amnion, and chorion. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. extraembryonic extrafloral Related Content Daily Word Quiz: cetacean Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language