/ Dictionary / Index Z zillionaire: Meaning and Definition of Find definitions for: zil•lion•aire Pronunciation: (zil"yu-nâr'), [key] — n. Informal. a person of incalculably great wealth. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. zillion Zilpah Related Content Daily Word Quiz: eureka Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language