/ Dictionary / Index O OSD: Meaning and Definition of Find definitions for: OSD Pronunciation: [key] Office of the Secretary of Defense. O.S.D. Pronunciation: [key] Order of St. Dominic (Dominican). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. osculum -ose 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