From Longman Dictionary of Contemporary Englishmildewmil‧dew /ˈmɪldjuː $ -duː/ noun [uncountable] HBMDECAYa white or grey substance that grows on walls or other surfaces in wet, slightly warm conditions —mildewed adjective
Examples from the Corpus
mildew• A nightmare of wilt and mildew, of fungus and blackspot.• Each of the three sails was then treated with a special liquid to discourage mildew and rot.• But before you do that, you can determine whether some of it is mildew by wiping a small area with bleach.• Keep aster plants well watered to help prevent attacks of mildew.• He examined them carefully for signs of mildew before putting them on.• But the floors feel spongy with moisture, and the air is saturated with the smell of mildew and fried fish.• It was air that seemed to have been trapped in here for decades, and which smelled of mildew.• On top was a rug, colourless with age and stained with mildew.Origin mildew Old English meledeaw “sweet sticky substance from plants” 