deterioration
/di-ˌtir-ē-ə-ˈrā-shən/
noun
the action or process of becoming impaired or inferior in quality, functioning, or condition : the state of having deteriorated
rust deterioration
deterioration degeneration decadence decline mean the falling from a higher to a lower level in quality, character, or vitality. deterioration implies generally the impairment of value or usefulness. degeneration stresses physical, intellectual, or especially moral retrogression.