/ Dictionary / Index M mydriasis: Meaning and Definition of Find definitions for: my•dri•a•sis Pronunciation: (mi-drī'u-sis, mī-), [key] — n. Med. excessive dilatation of the pupil of the eye, as the result of disease, drugs, or the like. Cf. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: mydriasis (Thesaurus) mycovirus mydriatic 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