Abatement

From Middle French abatement, from Old French abatre

CDOE|page=2

. Equivalent to abate("to beat down") + -ment("the result of").

Full definition of abatement

(plural abatements)

The act of abating, or the state of being abated; a lessening, diminution, or reduction; a moderation; removal or putting an end to; the suppression of. First attested from 1340 to 1470.

SOED5|page=2

the abatement of a nuisance is the suppression thereof.
The amount abated; that which is taken away by way of reduction; deduction; decrease; a rebate or discount allowed; in particular from a tax. Late 15^th century.
(heraldry) A mark of dishonor on an escutcheon; any figure added to the coat of arms tending to lower the dignity or station of the bearer.

Early 17^th century.

From Middle English, from Anglo-Norman abatre ("to abate") + -ment.

MW3 1976

(plural abatements)

(legal) The action of a person that abates, or without proper authority enters a residence after the death of the owner and before the heir takes possession.
(legal) The reduction of the proceeds of a will, when the debts have not yet been satisfied; the reduction of taxes due.

RHCD|page=1First attested around 1150 to 1350.