/ Dictionary / Index M MDR: Meaning and Definition of Find definitions for: MDR Pronunciation: [key] minimum daily requirement. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. mdnt. mdse. Related Content Daily Word Quiz: tactful Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language