A bustle is a type of framework used to expand the fullness or support the drapery of the back of a woman's dress, occurring predominantly in the mid-to-late 19th century. Bustles were worn under the skirt in the back, just below the waist, to keep the skirt from dragging. Heavy fabric tended to pull the back of a skirt down and flatten it. Thus, a woman's petticoated or crinolined skirt would lose its shape during everyday wear (from merely sitting down or moving about). The word "bustle" has become synonymous with the fashion to which the bustle was integral.