/ Dictionary / Index E endoderm: Meaning and Definition of Find definitions for: en•do•derm Pronunciation: (en'du-dûrm"), [key] — n. Also calledthe innermost cell layer of the embryo in its gastrula stage. the innermost body tissue that derives from this layer, as the gut lining. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: endoderm (Thesaurus) endocytosis endodermis Related Content Daily Word Quiz: hedonist Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language