/ Dictionary / Index B Boniface IX: Meaning and Definition of Find definitions for: Boniface IX Pronunciation: [key] — (Pietro Tomacelli) died 1404, Italian ecclesiastic: pope 1389–1404. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Boniface VIII boning knife Related Content Daily Word Quiz: fidelity Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language