1 : (anatomy) a layer (a lining or membrane) that encloses a structure
2 : (construction) a layer of masonry
3 : an abstract place usually conceived as having depth
4 : a thin layer covering something
5 : a relative position or degree of value in a graded group
6 : people having the same social, economic, or educational status
7 : a decorative texture or appearance of a surface (or the substance that gives it that appearance)