[Last Updated: 05-14-03 -- - - - [outdated] - - - -- atrophy Pronunciation Key (atro-fee) n. pl. atrophies Pathology. A wasting or decrease in size of an organ, tissue, or part owing to disease, injury, or lack of use: muscular atrophy of a person affected with paralysis. A wasting away, deterioration, or diminution: intellectual atrophy.