/ Dictionary / Index M millionairess: Meaning and Definition of Find definitions for: mil•lion•air•ess Pronunciation: (mil"yu-nâr'is), [key] — n. a woman who is a millionaire. the wife of a millionaire. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: millionairess (Thesaurus) millionaire million electron volts Related Content Daily Word Quiz: panacea Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language