1. A disorder caused by defective nutrition or metabolism.
2. In medicine, progressive degeneration of a body tissue; for example, a muscle, as a result of inadequate nourishment of the affected part, due to some unknown cause.
3. A condition in which pond or lake water is unable to support thriving animal or plant life because of excessive humus content.

Dystrophy (disorder arising from defective or faulty nutrition) of the fingernails and the toenails.