depreciation　

depreciation　1，折旧2.贬值　

1.the allocation of the cost of assets to periods in which the assets are used（depreciation with the matching principle），which results in the decrease in value of assets（fair value depreciation）.2.the gradual decrease in the economic value of the capital stock of a firm，nation or other entity，either through physical depreciation，obsolescence or changes in the demand for the services of the capital in question.