Breadcrumb Home > 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: nabob Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language