IPA: /ˈwɛtpruːf/
KK: /ˈwɛtpruf/
Something that is resistant to water and does not allow it to pass through.
The wetproof jacket kept me dry during the rain.
Wetproof → It is formed from "wet" (from Old English *wæt*, meaning moist or damp) and "proof" (from Old English *prōf*, meaning test or trial). The word "wetproof" means resistant to moisture or able to withstand wet conditions.
Think of something that is 'moist' ('wet') and can withstand a 'test' ('proof') against water — that's what wetproof means.