Emily Dickinson Lexicon

MILDEW, n. [Sax. mildeaw; L. melligo, from mel, honey; G. mehlthau, as if from mehl, meal.]

1. Honey dew; a thick, clammy, sweet juice, found on the leaves of plants, which is said to injure the plants by corroding them, or otherwise preventing them from coming to perfection. Encyc.
2. Spots on cloth or paper caused by moisture.