What does amortize mean?
The definition of amortize
A*mor”tize, v. t.
Etym: [OE. amortisen, LL. amortisare, admortizare, F. amortir to sell in mortmain, to extinguish; L. ad + mors death. See Mortmain].

1 To make as if dead; to destroy. [Obs.] Chaucer.
2 (Law)
To alienate in mortmain, that is, to convey to a corporation. See Mortmain.
3 To clear off or extinguish, as a debt, usually by means of a sinking fund.