French for 'to kill' a debt slowly — from Latin 'mors' (death), each payment a small execution.
To gradually write off the initial cost of an asset over a period; to gradually reduce or pay off a debt with regular payments.
From Old French 'amortir' (to deaden, extinguish, kill), from Vulgar Latin '*admortīre' (to bring to death), from Latin 'ad-' (to, toward) and 'mors,' genitive 'mortis' (death). The original sense was to 'kill' a debt or to transfer property to a 'dead hand' (mortmain) — an ecclesiastical corporation that, unlike a mortal individual, never dies and therefore never surrenders the property. The financial sense of gradual debt reduction developed in the eighteenth century
The concept of 'mortmain' (dead hand) — property held by an institution that never dies — was so alarming to medieval English kings that they passed Statutes of Mortmain in 1279 and 1290 to restrict the Church from accumulating land. Because a corporation never dies, land given to the Church was effectively 'killed' — removed permanently from the feudal system of inheritance and taxation. Amortization was originally this process of killing property by