mildew

 Longman Dictionary of Contemporary English 5++朗文当代英语 5++LDOCE 5++朗文 5++mil·dew /ˈmɪldjuː $ -duː/ noun [uncountable]  HBMDECAYa white or grey substance that grows on walls or other surfaces in wet, slightly warm conditions 霉；霉菌 —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”

mil·dew nounChineseSyllable  

walls Corpus a that white grows on or substance grey

mildew
mil‧dew /ˈmɪldjuː $ -duː/ noun [uncountable]a white or grey substance that grows on walls or other surfaces in wet, slightly warm conditions
—mildewed adjective

mil·dewBrE /ˈmɪldjuː/ 🔊NAmE /ˈmɪlduː/ 🔊 noun [uncountable] a very small white fungus that grows on walls, plants, food, etc. in warm wet conditions 霉；霉菌