Impairer n. : One who, or that which, impairs.

Example:


Taxonomy
Dictionary, adjective, impair, Synonyms, Pronunciation, damage, word origin, impairment, driver, Origin, health, mental disability, driving under the influence of alcohol, equiv, Latin, Houghton Mifflin Company, transitive verb, Merriam-Webster, Inc.

Defination from the web:
Impaired - Definition of Impaired at Dictionary.com a free online dictionary with pronunciation, synonyms, and translation of Impaired. Word of the Day and Crossword Puzzles. ... strength, value, or quality: an injury that impaired my hearing; a severe storm impairing communications. ...