/ Dictionary / Index E endosome: Meaning and Definition of Find definitions for: en•do•some Pronunciation: (en'du-sōm"), [key] — n. Cell Biol. a smooth sac within the cell, formed by or fused with coated vesicles that shed their clathrin, in which ligands are separated from their receptors and from which the receptors are returned to the cell surface. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. endosmosis endosperm Related Content Daily Word Quiz: gregarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language