What is a "bustle"?

A bustle is a type of framework or padding used to enhance the shape of the back of a woman's dress or skirt, typically worn in the late 19th and early 20th centuries. The bustle was designed to give a fashionable fullness to the back of a skirt, creating a distinctive "pouf" effect. It was often made of horsehair or steel and could be adjusted to create different levels of fullness. Bustles were popular during the Victorian era and were worn by women of all social classes. They fell out of fashion in the early 20th century as skirts became more streamlined, but have continued to be worn in some forms for special occasions and historical reenactments.