lining means: Lining, a fabric layer like silk or fur that gives a finished look — hiding seam allowances or other construction details. Linings are also a way to add insulation, or strengthen shapes or silhouettes, especially in tailoring. (in Fashion Dictionary)

What else does lining mean?

An interior surface coating or covering. (in Merlin Dictionary)

This material is used to cover or coat. (in Merlin Dictionary)