abater

noun

1. One who, or that which, abates.

   “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.”

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

   “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.”

   “[…] 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.”