<p><strong>Adjective</strong></p><ul><li>Impervious to water</li><li>Rendered impervious to water by some special process, as coating or treating with rubber: a waterproof hat</li></ul><p><strong>Noun</strong></p><ul><li>Chiefly British: a raincoat or other outer coat impervious to water</li><li>Any of several coated or rubberized fabrics that are impervious to water</li></ul><p><strong>Verb</strong></p><ul><li>(Used with object) to make waterproof</li></ul>