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