/ Dictionary / Index P Pius X: Meaning and Definition of Find definitions for: Pius X Pronunciation: [key] (Giuseppe Sarto), 1835–1914, Italian ecclesiastic: pope 1903–14. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Pius IX Pius XI Related Content Daily Word Quiz: pugilist Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language