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