- Decrease in the size of a cell, tissue, organ, or multiple organs, associated with a variety of pathological conditions such as abnormal cellular changes, ischemia, malnutrition, or hormonal changes.
Definition from: MeSH via Unified Medical Language System at the National Library of Medicine
- Decrease in size or wasting away of a body part or tissue; also: arrested development or loss of a part or organ incidental to the normal development or life of an animal or plant.
Definition from: Merriam-Webster's Medical Dictionary by Merriam-Webster Inc.
See also Understanding Medical Terminology.