/ Dictionary / Index O ordn.: Meaning and Definition of Find definitions for: ordn. Pronunciation: [key] ordnance. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. ordination ordnance Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language