Amortization - The gradual extinguishment of the amount of an asset, liability, profit or loss, prorating it over the period
during which it will exist or during which its benefit will be realized.
-   The gradual extinction of a debt, as, for instance, by means of a sinking fund.
-   The gradual reduction in the valuation of an asset, thus anticipating the time when it shall eventually become worthless.
-   The absorption in the Income or Profit and Loss accounts, during the pendency of the debt, of a discount incurred or of        
         a premium realized in the sale of an obligation.

The extinction or reduction of a debt by means of a sinking fund.