The term 'Made of a Certain Grain' can be summarized by two crossword solutions: OATEN (5 letters) and OATY (4 letters). OATEN and OATY refer to something made of oats, a type of cereal grain. Oats are a popular grain used in many foods, such as oatmeal, granola, and muesli. They are also used to make flour, which is used in baking. Oats are a nutritious grain, high in fiber and protein, and are often used in health foods.