/ Dictionary / Index M Messidor: Meaning and Definition of Find definitions for: Mes•si•dor Pronunciation: (me-sē-dôr'), [key] — n. (in the French Revolutionary calendar) the tenth month of the year, extending from June 19 to July 18. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: messidor (Thesaurus) messianism Messier 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