The crossword solution for the term 'WAY TO DECREASE?' is 'IRON' (4 letters). IRON is a chemical element that is commonly used to reduce or decrease the amount of something. It is often used in industrial processes, such as steel production, to reduce the amount of impurities in the final product. IRON can also be used to reduce the amount of pollutants in water, air, and soil. In addition, IRON is an essential nutrient for humans and animals, and it helps to reduce the risk of certain diseases.