The term 'THIN OUTER LAYER' can be summarized by two crossword solutions: SKIN (4 letters) and VENEER (6 letters). SKIN is the outermost layer of the human body, composed of multiple layers of cells that provide protection from the environment. VENEER is a thin layer of material applied to the surface of an object to give it a smooth finish or to conceal imperfections. It is often used in woodworking and construction.