ETYM AS. meledeáw; akin to Old High Germ. militou, German mehlthau, mehltau; prob. orig. meaning, honeydew; cf. Goth. milip honey. Related to Mellifluous, and Dew.
1. A fungus that produces a superficial (usually white) growth on organic matter.
2. The process of becoming mildewed; SYN. mold.
Any fungus that appears as a destructive growth on plants, paper, leather, or wood when exposed to damp; such fungi usually form a thin white coating.

1. To become tainted with mildew.
2. (Figuratively) To fall into disuse