/ Dictionary / Index S Sylvester I: Meaning and Definition of Find definitions for: Sylvester I Pronunciation: [key] dieda.d.335, pope 314–335. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Sylvester Sylvester II 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