accumulated amortization
noun[U]
ACCOUNTINGukusthereductioninvalueof anintangibleasset(= anassetthat is not aphysicalthing)since it has beenowned:
AccumulatedamortizationatDecember31 oncostsallocatedtopatents,tradenames, and otherintangibleassetswas $48.2 million.
Compare
accumulated depreciation