/ Dictionary / Index O operating income: Meaning and Definition of Find definitions for: op'erating in"come Pronunciation: [key] revenue from business operations after operating expenses are deducted from gross income. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. operating operating room Related Content Daily Word Quiz: dormant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language