Home › Words › M › mothproofermothproofermothproofer means any substance used to make things mothproof.Among words judged in Lexicurio's Arena, mothproofer ranks #23,621 of 42,820 for Qualifying.EtymologyFrom mothproof + -er.nounAny substance used to make things mothproof.e.g.“The dye-bath mothproofers are permanent-type mothproofers which are as the name implies applied in the dye bath.” — 1964, Arnold Mallis, Handbook of Pest Control: The Behavior, Life History, and Control of Household Pests, MacNair-Dorland Company:Definitions & examples from Wiktionary (CC BY-SA 3.0).