Definition of "lining"

A canister of flour from the kitchen had been thrown at the looking-glass and lay like trampled snow over the remains of a decent blue suit with the lining ripped out which lay on top of the ruin of a plastic wardrobe.

1963, Margery Allingham, “Foreword”, in The China Governess‎

The lobule margins, furthermore, are arched away from the lobe, with the consequence that (when fully inflated) the abaxial leaf surface forms the interior lining of the lobule.

1992, Rudolf M[athias] Schuster, The Hepaticae and Anthocerotae of North America: East of the Hundredth Meridian, volume V, New York, N.Y.: Columbia University Press, page 7

As we age, the major arteries of our bodies frequently become thickened with plaque, a fatty material with an oatmeal-like consistency that builds up along the inner lining of blood vessels.

2013 July-August, Stephen P. Lownie, David M. Pelz, “Stents to Prevent Stroke”, in American Scientist