depreciation
dɪˌpriːʃɪˈeɪʃ(ə)n
noun
a reduction in the value of an asset over time, due in particular to wear and tear.
provision should be made for depreciation of fixed assets
devaluation,devaluing,decrease in value,lowering in value,reduction in value,cheapening,markdown,reduction,decline,downturn,downswing,drop,slump,plunge,tumble,downtick,nosedive,crash