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