bustle means: The ‘bubble’, or padding worn behind a skirt is called bustle. It can be either under or in the fabric. You can use it as a drape, twist or fabric or a frame of layers. It is intended to emphasize the feminine appeal of your behind. The bustle was popular in Victorian times, especially when crinolines and women were corseted. It adds volume below the waist. Although it can be used with ribbons or bows, its original purpose is to draw the skirt down and prevent the hems from sliding in the mud. (in Fashion Dictionary)

What else does bustle mean?

1. A term that refers to the back of a skirt’s fullness. 2. An undergarment that is designed to support the skirt’s back. From 1870-1890, women’s skirts featured a prominent feature: the bust. Evening dresses often see fullness restored by designers. (in Fashion Dictionary)