/ Dictionary / Index L Leo X: Meaning and Definition of Find definitions for: Leo X Pronunciation: [key] — (Giovanni de'Medici), 1475–1521, Italian ecclesiastic: pope 1513–21 (son of Lorenzo de'Medici). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Leo IX Leo XI 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