The term 'Symbol of Toughness' can be represented by two words: STEEL and Nails. STEEL is an alloy of iron and other elements, such as carbon, that is widely used in construction and other industries due to its strength and durability. Nails are a common fastener made of STEEL, and are used to join two pieces of material together. Both STEEL and nails are symbols of toughness, and are often used in construction projects to ensure the structure is strong and secure.