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