/ Dictionary / Index O Oldcastle: Meaning and Definition of Find definitions for: Old•cas•tle Pronunciation: (ōld'kas"ul, -kä"sul), [key] 1377–1417, English martyr: leader of a Lollard conspiracy; executed for treason and heresy; model for Shakespeare's Falstaff. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Old Castile Old Catholic Related Content Daily Word Quiz: cautious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language