/ Dictionary / Index M miosis: Meaning and Definition of Find definitions for: mi•o•sis Pronunciation: (mī-ō'sis), [key] — pl. -ses excessive constriction of the pupil of the eye, as a result of drugs, disease, or the like. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: miosis (Thesaurus) Miocene miotic 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