Pilot cloth is a heavy, coarse fabric that is commonly used in making outerwear and work clothes. This fabric is known for its durability and resistance to water and wind. However, there are several synonyms for pilot cloth that are equally sturdy and useful. Some of these synonyms include duck cloth, canvas, twill, and denim. Duck cloth is a heavy, plain-woven fabric that is similar to canvas. Canvas is a coarse, durable fabric that is commonly used for sails, tents, and outdoor gear. Twill is a fabric that has a diagonal weave, providing it with added strength and a unique texture. Denim is a cotton fabric that is tightly woven and known for its durability and toughness.