Foul rags refer to dirty, stained or torn pieces of cloth used as cleaning material. There are various synonyms for this term, including grease cloths, cleaning rags, and wiping cloths. They are often made from discarded clothing like old t-shirts or towels and are used in industrial settings like garages, workshops, and factories. Other synonyms for foul rags include shop towels, dust rags, and oily rags. These cleaning materials are essential for maintaining cleanliness and hygiene in different work environments and are necessary for keeping tools and machinery clean. While they may be considered dirty, they serve as an important tool in keeping our surroundings free from germs and dirt.