Pronunciation: (mil'dOO", -dyOO"),[key] —n. 1. Plant Pathol.a disease of plants, characterized by a cottony, usually whitish coating on the surface of affected parts, caused by any of various fungi.
2. any of these fungi. Cf. downy mildew, powdery mildew. 3. any of similar coatings or discolorations, caused by fungi, as that which appears on fabrics, paper, leather, etc., when exposed to moisture.
—v.t., v.i. to affect or become affected with mildew.