/ Dictionary / Index M muscular dystrophy: Meaning and Definition of Find definitions for: mus'cular dys'trophy Pronunciation: [key] a hereditary disease characterized by gradual wasting of the muscles with replacement by scar tissue and fat, sometimes also affecting the heart. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. muscular musculature Related Content Daily Word Quiz: nonchalant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language