/ Dictionary / Index L Leo IV: Meaning and Definition of Find definitions for: Leo IV Pronunciation: [key] — Saint, died a.d. 855, Italian ecclesiastic: pope 847–855. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Leo III Leo V Related Content Daily Word Quiz: penchant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language