/ Dictionary / Index O oillionaire: Meaning and Definition of Find definitions for: oil•lion•aire Pronunciation: (oil"yu-nâr'), [key] — n. Canadian Informal. a millionaire whose wealth is derived from the petroleum industry. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. oillet oilman Related Content Daily Word Quiz: ablution Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language