<p><strong>Noun</strong></p><ul><li>a disease of plants, characterized by a cottony, usually whitish coating on the surface of affected parts, caused by any of various fungi.</li><li>any of these fungi.</li><li>any of similar coatings or discolorations, caused by fungi, as that which appears on fabrics, paper, leather, etc., when exposed to moisture.</li></ul><p><strong>Verb</strong></p><ul><li>to affect or become affected with mildew.</li></ul>