decrease in value due to wear and tear, decay, decline in price, etc.

such a decrease as allowed in computing the value of property for tax purposes.

a decrease in the purchasing or exchange value of money.

a lowering in estimation.

noun

accounting allowance , deflation , fall , loss of value , reduction , slump , devaluation , markdown , write-down , denigration , deprecation , derogation , detraction , disparagement , minimization