/ Dictionary / Index O O.S.F.: Meaning and Definition of Find definitions for: O.S.F. Pronunciation: [key] Order of St. Francis (Franciscan). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Osetic OSFCW Related Content Daily Word Quiz: crutiny Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language