waterproofPronunciation: /ˈwɔːtəpruːf/Translate waterproof | into French | into German | into Italian | into Spanish Definition of waterproof adjective impervious to water:a waterproof hat not liable to be washed away by water:waterproof ink noun British a garment, especially a coat, that keeps out water: she put on boots and a waterproof verb [with object] make impervious to water: a plastic case waterproofs this disposable cameraDerivatives waterproofer noun waterproofness noun waterproof in other Oxford dictionaries Definition of waterproof in the US English dictionary