/ Dictionary / Index I iono-: Meaning and Definition of Find definitions for: iono- Pronunciation: [key] a combining form with the meanings “ion,” “ionized,” “ionosphere,” used in the formation of compound words: ionophore. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. ionizing radiation ionogen Related Content Daily Word Quiz: pundit Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language