amortization (n.)

late 14c., amortisen, in law, "to alienate lands," also (c. 1400) "to deaden, destroy;" from Old French amortiss-, present-participle stem of amortir "deaden, kill, destroy; give up by right" (12c.), from Vulgar Latin *admortire "to extinguish," from ad "to" (see ad-) + mortus "dead," from Latin mors "death" (from PIE root *mer- "to rub away, harm").

The literal sense "make dead" is obsolete in English. In reference to extinguishing a debt from early 19c. Related: Amortized; amortizing.

chiefly British English spelling of amortization; see -ize.