mothproofPronunciation: /ˈmɒθpruːf/Translate mothproof | into German | into Italian Definition of mothproof adjective (of clothes or fabric) treated with a substance which repels moths: a garment that is fully washable, mothproof, and flame resistant verb [with object] treat (clothes or fabric) with a substance which repels moths: when storing a rug, first have it cleaned, washed, and mothproofedmothproof in other Oxford dictionaries Definition of mothproof in the US English dictionary