Definition
To alien or convey land into mortmain — that is, to transfer real property to a corporation or ecclesiastical body in such a way that it passes out of ordinary feudal circulation and becomes perpetually "dead" to the crown and feudal lords. The term is the Law French root form of the more commonly encountered AMORTISE or AMORTIZE in its historical English legal sense. The conveyance was regarded as harmful to the feudal system because land held by corporations could not escheat, could not generate feudal incidents (relief, wardship, marriage), and effectively became inalienable in perpetuity. English statutes from the reign of Edward I onward regulated or prohibited such conveyances without royal license.
Common Language
Modern common usage (Wiktionary): To amortize means to gradually write off or reduce a debt or asset value over a period of time; in finance, to pay off a loan through scheduled installment payments.
Historical common usage (Webster's 1913): "Amortize" — to alienate in mortmain, that is, to convey to a corporation; also, in later use, to put beyond the power of alienation.
The gap here is substantial and cuts in both directions. The modern common meaning (debt reduction, loan repayment schedules) is entirely financial and has no connection to land tenure or feudal law. A researcher encountering "amortir" or "amortize" in historical legal texts must resist importing the modern financial sense. The shared root — mort, death — links both uses conceptually (a debt is "killed off"; land is made "dead to commerce"), but the legal and financial senses are functionally unrelated and separated by centuries of semantic drift.
Common Confusion
AMORTIR / AMORTISE / AMORTIZE: These three forms appear interchangeably in historical sources, with AMORTIR being the Law French form, AMORTISE the anglicized legal form most common in statutes and commentaries, and AMORTIZE appearing in later usage. They denote the same act. Researchers should not treat them as distinct terms. The confusion arises when AMORTIZE is encountered in a historical source and read through a modern financial lens — the financial sense is a later and separate development.
Why It Matters in Research
This term is a navigational trap for researchers working in English legal history before the nineteenth century. Three specific risks:
First, the term appears almost exclusively in sources dealing with the mortmain statutes — principally the Statute of Mortmain (De Viris Religiosis, 7 Edw. I, 1279), the Statute of Westminster (37 Edw. I, st. 2), and the Mortmain Act of 1736. Researchers working in ecclesiastical law, real property, or charitable trusts will encounter it; researchers in other areas almost never will.
Second, Burrill cross-references AMORTISE and AMORTIZE as the operative English forms, with AMORTIR flagged as the Law French antecedent. When searching corpus materials, run searches on all three spellings, as historical texts are inconsistent. Cowell's Interpreter and Blackstone's Commentaries (2 Bl. Com. 272) use AMORTISE; older Year Books and plea rolls may use AMORTIR or Latinized variants.
Third, the term connects corpus materials in ways that are not obvious from the headword alone. A document using AMORTIR is almost certainly touching questions of royal license, corporate capacity to hold land, and the ecclesiastical exemptions that animated centuries of conflict between church and crown. These connections point researchers toward a distinct cluster of materials — mortmain, frankalmoign, superstitious uses, and the dissolution-era statutes — that may not surface in a narrower keyword search.
Historical Dictionary Support
Burrill's Law Dictionary is the sole shelf source for this entry, and it handles the term economically. Burrill correctly identifies AMORTIR as the Law French form, supplies the Latin variant (amortizare), and immediately cross-references AMORTISE as the operative headword, where the key statutory citations appear: Stat. 37 Edw. I st. 2 and Stat. 15 Ric. II c. 5. Burrill also cites 2 Blackstone's Commentaries 272 and Shelford on Mortmain — both authoritative secondary sources on the doctrine.
What Burrill does not do, understandably given its period, is flag the later semantic divergence toward the financial meaning of "amortize." Researchers consulting Burrill on this term are well-served for historical land law purposes but should not rely on it as a guide to the term's modern usage trajectory.
No other shelf sources in the current Law Mind corpus carry a dedicated entry for AMORTIR specifically, though the doctrine it names is addressed under MORTMAIN across multiple historical dictionaries.
Jurisdictional Note
The doctrine of mortmain, and therefore the legal sense of AMORTIR, is primarily an English common law concept. It did not transplant with full force into American law — most American states abolished mortmain restrictions in the nineteenth century or never adopted them. Researchers encountering AMORTIR in American legal sources should treat such appearances as either quotations from English authority or artifacts of early colonial-era practice.