/ Dictionary / Index M marginal utility: Meaning and Definition of Find definitions for: mar'ginal util'ity Pronunciation: [key] the extra utility or satisfaction derived by a consumer from the consumption of the last unit of a commodity. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. marginal sea marginate Related Content Daily Word Quiz: winsome Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language