1.NounThe state of being depreciated; disparagement.
2.NounThe decline in value of assets.
"asset depreciation; currency depreciation; The accountant calculated the annual depreciation of the machinery.; There was a sharp depreciation in the value of the currency."
3.NounThe measurement of the decline in value of assets. Not to be confused with impairment, which is the measurement of the unplanned, extraordinary decline in value of assets.