Noun

1. The act of reducing in rank, character, or reputation, or of abasing; a lowering from one's standing or rank in office or society; diminution; as, the degradation of a peer, a knight, a general, or a bishop.
2. The state of being reduced in rank, character, or reputation; baseness; moral, physical, or intellectual degeneracy; disgrace; abasement; debasement.
3. Diminution or reduction of strength, efficacy, or value; degeneration; deterioration.
4. A gradual wearing down or wasting, as of rocks and banks, by the action of water, frost etc.
5. A deleterious change in the chemical structure, physical properties or appearance of a material from natural or artificial exposure.
6. The state or condition of a species or group which exhibits degraded forms; degeneration.
7. Arrest of development, or degeneration of any organ, or of the body as a whole.
8. The gradual breakdown of components of a material, as a result of a natural element, i.e.: heat, cold and wind.