A "daub" refers to a small amount of a substance, often applied in a rough or careless manner. It is commonly used in art to describe the application of paint or other materials on a surface. For example, an artist might daub paint onto a canvas to create texture or to quickly convey an idea. In a broader context, the term can also refer to any hasty or clumsy application of a material, such as plaster or mud. This technique can be seen in various forms of construction or craft, where a daub is used to fill gaps or create a specific effect.