If something is rainproof, rain cannot get through it. A rainproof coat, bag, or tent is meant to keep you or your things dry when it rains. You can also use it as a verb: to rainproof a jacket is to treat it so that rain stays out. It sits next to waterproof, and many people use the two as if they were the same. Though actually, rainproof talks about rain in particular; waterproof is the bigger claim — water of any kind, not only rain. In shops, waterproof is the word you will hear more often.

防雨的