covering
/ˈkʌvərɪŋ/noun
1- a thing used to cover something else, typically in order to protect or conceal it（用于保护或隐藏别的东西的）覆盖物; 遮蔽物：
a vinyl floor covering
聚乙烯塑料地毯。
1.1
- usu. in sing. a layer of something that covers something else遮蔽（或覆盖）物的一层：
the sky was obscured by a covering of cloud.
天空被云层遮得暗了。