/ Dictionary / Index E endo-: Meaning and Definition of Find definitions for: endo- Pronunciation: [key] a combining form meaning “within,” used in the formation of compound words: endocardial. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. endnote endobiotic Related Content Daily Word Quiz: paradox Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language