The term 'COIN' is a four-letter solution to the crossword puzzle and can be used to describe either a nickel or a dime. Both coins are part of the United States currency and are made of metal. The nickel is worth five cents, while the dime is worth ten cents. The nickel is slightly larger than the dime and has a picture of Thomas Jefferson on one side. The dime has a picture of President Franklin D. Roosevelt on one side.