/ Dictionary / Index M m'sieur*: Meaning and Definition of Find definitions for: m'sieur Pronunciation: (mu-syœ'), [key] — French. French. contraction of monsieur. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. M.S.I.E. M.S.J. Related Content Daily Word Quiz: cautious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language