/ Dictionary / Index I Ionian mode: Meaning and Definition of Find definitions for: Io'nian mode" Pronunciation: [key] — Music. Music. an authentic church mode represented on the white keys of a keyboard instrument by an ascending scale from C to C. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Ionian Islands Ionian Sea Related Content Daily Word Quiz: spectral Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language