amortization

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The act or process of amortizing.
• noun The money set aside for this purpose.
• noun In reckoning the yield of a bond bought at a premium, the periodic subtraction from its current yield of a proportionate share of the premium between the purchase date and the maturity date.

from The Century Dictionary.

• noun The act of alienating lands or tenements to a corporation in mortmain.
• noun Extinction, as of debt, especially by a sinking-fund; a payment toward such extinction.
• noun Also admortization, amortizement.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Law) The act or right of alienating lands to a corporation, which was considered formerly as transferring them to dead hands, or in mortmain.
• noun The extinction of a debt, usually by means of a sinking fund; also, the money thus paid.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The reduction of loan principle over a series of payments.
• noun The distribution of the cost of an intangible asset, such as an intellectual property right, over the projected useful life of the asset.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the reduction of the value of an asset by prorating its cost over a period of years
• noun payment of an obligation in a series of installments or transfers