/ Dictionary / Index M mitral stenosis: Meaning and Definition of Find definitions for: mi'tral steno'sis Pronunciation: [key] abnormal narrowing of the mitral valve usually resulting from disease, as rheumatic fever, and obstructing the free flow of blood from the atrium to the ventricle. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. mitral insufficiency mitral valve Related Content Daily Word Quiz: belligerent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language