n.[C]

1. 框；殼；罩；套
   This wire has a plastic casing.

   這種電線外包塑膠。

   There is a window fitting in a casing.

   有一扇裝在框內的窗。

2. 箱；盒
3. （輪的）外胎；（香腸的）腸衣；（油井的）套管

1. case的動詞現在分詞、動名詞

n.

1. a cover or shell that protects or encloses something.
2. the frame round a door or window.