名词

1. 罩;管;套;盒
A casing is a substance or object that covers something and protects it.

1. the enclosing frame around a door or window opening

e.g. the casings had rotted away and had to be replaced

Synonym: case

2. the outermost covering of a pneumatic tire

3. the housing or outer covering of something

e.g. the clock has a walnut case

Synonym: shellcase