mothproof Syllabification: (moth·proof)Pronunciation: /ˈmôTHˌpro͞of/Translate mothproof | into German | into Italian Definition of mothproof adjective (of clothes or fabrics) treated with a substance that repels moths. verb [with object] treat with a substance that repels moths. mothproof in other Oxford dictionaries Definition of mothproof in the British & World English dictionary