/ Dictionary / Index O O'Fallon: Meaning and Definition of Find definitions for: O'Fal•lon Pronunciation: (ō-fal'un), [key] — n. a town in SW Illinois. 10,217. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. of O'Faoláin Related Content Daily Word Quiz: panacea Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language