The term 'It's Been Through the Mill' can be summarized by the crossword solution of 'FLOUR, ' which is a powder made by grinding raw grains or roots. FLOUR is a staple ingredient in many baked goods and is used to thicken sauces and soups. It is also used to make bread, pasta, and other foods. FLOUR is produced by milling, which is the process of grinding grains or other plant materials into a fine powder.