In the 15th century, the term nap refers to a pile given to the cloth. The word pile means the raised fibers that are there on purpose. They were put there, instead of by producing the cloth. The nap is woven into the cloth, often by weaving loops into the fabric. The can then be cut or left on the cloth. Carpets, rugs, velvet, velour, and velveteen, are made by weaving a second yarn through woven cloth, making a nap or pile.
- "Nap". Encyclopedia Britannica Eleventh Edition. 1911.
- "Nap." The Oxford English Dictionary. 2nd ed. 1989.
- "Pile." The Oxford English Dictionary. 2nd ed. 1989.