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