mildew
mil·dew
noun \ˈmil-ˌd(y)ü\Definition of MILDEW
1
: a superficial usually whitish growth produced especially on organic matter or living plants by fungi (as of the families Erysiphaceae and Peronosporaceae)
2
: a fungus producing mildew
Learn More About
Seen & Heard 
What made you want to look up mildew? Please tell us where you read or heard it (including the quote, if possible).
