A growth of minute powdery or webby fungi, whitish or of different colors, found on various diseased or decaying substances.
- Any of various fungi that form a superficial, usually whitish growth on plants and various organic materials.
- A superficial coating or discoloration of organic materials, such as cloth, paper, or leather, caused by fungi, especially under damp conditions.
- A plant disease caused by such fungi.
- To affect or become affected with mildew.