1. Progressive degeneration of a body tissue; such as, muscle, caused by inadequate nourishment of the affected part, as a result of some unknown cause.
2. A condition in which pond or lake water is unable to support much plant or animal life because of an excessive amount of humus content.
3. In medicine, a degenerative, faulty, or inadequate nutrition or development.
4. In pathology, any of a number of disorders characterized by weakening, degeneration; especially, muscular dystrophy, in which the muscles weaken and atrophy.

A group of chronic muscle diseases of genetic or unknown origin that cause irreversible muscle deterioration and may result in complete incapacitation.