abater

plural abaters

1. One who, or that which, abates.First known use 16ᵗʰ century.

   1908, John H. Wallace, Preservation of the Game, Fish and Forests of Alabama, address given before the Alabama Press Association, 23 July, 1908, State Printers and Binders, p. 6, As a fever germ abater in a malarial district, a flock of bull-bats is worth a grove of quinine trees.

   3 more examples

   This is the great Prince of Grecia, called the Knight of the Sunne, restorer of the auncient kingdome of Tinacria, & the abater and breaker of the strength of the most strongest Giants in all the world.

   1583, Pedro de la Sierra, translated by Robert Parry, The Second Part of the Myrror of Knighthood, London: Thomas Este, Book 1, Part 2, Chapter 21

   Anodyne, or Abaters of Pain of the Alimentary Kind. Such things as relax the Tension of the affected nervous Fibres […]

   1732, John Arbuthnot, Practical Rules of Diet in the Various Constitutions and Diseases of Human Bodies, London: J. Tonson, Chapter 1, section 26, p. 281

   […] research is proving the effectiveness of trees and shrubs as noise abaters—research prompted by the growing awareness that excessive noise is a form of environmental pollution.

   1972, David I. Cook, David F. Van Haverbeke, “Trees and shrubs can curb noise, but with quite a few loud ‘ifs’”, in The Yearbook of Agriculture, 972, Washington, D.C.: US Department of Agriculture, page 28