outercover
nounUK /ˈaʊtəˌkʌvə/
US /ˈaʊtərˌkʌvər/
The outercover is the outside layer that keeps something safe.
The outercover of the book was torn after years of use.
OTHER MEANINGS
2. A removable protective sheet placed over a book's binding.
She slipped a plastic outercover over her library book.
3. The exterior fabric or material of a cushion or mattress.
The sofa's outercover can be unzipped and washed.
4. An outer protective housing on a machine or device.
The outercover of the motor protects it from dust.