/ Dictionary / Index L law of diminishing returns: Meaning and Definition of Find definitions for: law' of dimin'ishing returns' Pronunciation: [key] — Econ. Econ. See(def. 2). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. law of diminishing marginal utility law of excluded middle Related Content Daily Word Quiz: acerbity Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language