Amortization or amortisation is the process of decreasing or accounting for an amount over a period of time. The word comes from Middle English amortisen to kill, alienate in mortmain, from Anglo-French amorteser, alteration of amortir, from Vulgar Latin admortire to kill, from Latin ad- + mort-, mors death. Particular instances of the term include:

Amortization (business), the allocation of a lump sum amount to different time periods, particularly for loans and other forms of finance, including related interest or other finance charges.

Amortization schedule, a table detailing each periodic payment on a loan (typically a mortgage), as generated by an amortization calculator.

Negative amortization, an amortization schedule where the loan amount actually increases through not paying the full interest

Amortized analysis, analyzing the execution cost of algorithms over a sequence of operations.

Amortization of capital expenditures of certain assets under accounting rules, particularly intangible assets, in a manner analogous to depreciation.

Amortization (tax law)

Amortization is also used in the context of zoning regulations and describes the time in which a property owner has to relocate when the property's use constitutes a preexisting nonconforming use under zoning regulations.