amortize

Concise Oxford English Dictionary © 2008 Oxford University Press:
amortize /əˈmɔːtʌɪz/ (or amortise /əˈmɔːtʌɪz/)

▶verb

• 1 gradually write off the initial cost of (an asset) over a period.

  ■ reduce or pay off (a debt) with regular payments.

• 2 historical transfer (land) to a corporation in mortmain.

– derivatives
amortization noun.

– origin ME: from OFr. amortiss-, amortir, based on L. ad ‘to, at’ + mors, mort- ‘death’.