horsehair: a fabric made from fibers taken from the mane or tail of horses; used for upholstery
fabric: artifact made by weaving or felting or knitting or crocheting natural or synthetic fibers
mucus: protective secretion of the mucus membranes; in the gut it lubricates the passage of food and protects the epithelial cells; in the nose and throat and lungs it can make it difficult for bacteria to penetrate the body through the epithelium