The term CAT HAIR can be summarized by the crossword solution FUR, which is a three-letter word. FUR is the short, soft, and thick hair that covers the skin of many animals, including cats. It is made up of two layers: an inner layer of short, fine hairs called down, and an outer layer of longer, coarser hairs called guard hairs. FUR helps to keep animals warm and dry, and it also serves as camouflage.