The term 'Frock Fold' is a type of PLEAT, which is a fold in fabric that is made by doubling the material over itself and pressing it flat. It is commonly used in clothing to create a decorative effect or to provide extra fullness. The term 'Frock Fold' specifically refers to a type of PLEAT that is used in women's dresses and skirts, and is characterized by its wide, shallow shape. It is often used to add volume and texture to a garment, and can be seen in many different styles of clothing.