A "dun" is a term used to describe a type of hill or mound, often characterized by its rounded shape and gentle slopes. These natural formations can be found in various landscapes and are typically composed of soil, rock, or grass. Duns can serve as important ecological habitats, supporting diverse plant and animal life. In some contexts, "dun" also refers to a specific color, often a dull grayish-brown shade. This color is commonly associated with certain breeds of horses, such as the Dun horse, which features a light body color with darker markings. The term can also be used in other fields, such as art and design, to describe muted color palettes.