1. The process of degenerating.

2. The state of being degenerate.

3. Medicine Gradual deterioration of specific tissues, cells, or organs with corresponding impairment or loss of function, caused by injury, disease, or aging.

4. Biology The evolutionary decline or loss of a function, characteristic, or structure in an organism or species.

5. Electronics Loss of or gain in power in an amplifier caused by unintentional negative feedback.