/ Dictionary / Index I Iolanthe*: Meaning and Definition of Find definitions for: I•o•lan•the Pronunciation: (ī"u-lan'thē), [key] — n. an operetta (1882) by Sir William S. Gilbert and Sir Arthur Sullivan. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. I.O.F. iolite Related Content Daily Word Quiz: acquiesce Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language