am·or·ti·za·tion 
(ăm′ər-tĭ-zāshən, ə-môr′-)
(ăm′ər-tĭ-zāshən, ə-môr′-)n.
1.
a. The act or process of amortizing.
b. The money set aside for this purpose.
2. 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.