/ Dictionary / Index L Leo XI: Meaning and Definition of Find definitions for: Leo XI Pronunciation: [key] — (Alessandro de'Medici), 1535–1605, Italian ecclesiastic: pope 1605. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Leo X Leo XII 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