waterproof
adj. B1 Intermediate US //ˈwɔtɝˌpɹuf// UK //wˈɔːtəpɹˌuːf// wa·ter·proof
adj. not letting water in. You use this to describe clothes, bags, or materials that stay dry when it rains or gets wet.
adj. impervious to water; preventing moisture from penetrating a surface or material. Often used attributively before nouns like 'coat' or 'bag'.
This jacket is waterproof and keeps you dry.
She bought a waterproof backpack for her hiking trip.
The new smartphone features a waterproof design that protects internal components from accidental submersion in shallow water.
From water + -proof. Compare West Frisian wetterproef (“waterproof”), Dutch waterproef (“waterproof”).
Usage
Typically used attributively before a noun (e.g., 'waterproof boots'). Can also be used predicatively after 'be' (e.g., 'The boots are waterproof').