Farthingale n. : A hoop skirt or hoop petticoat, or other light, elastic material, used to extend the petticoat.

Example:
What in the world is a Farthingale?

Taxonomy
Spanish farthingale, fashion, shape, the French, free encyclopedia, 1590s, farthingales, hoops, England, garment, Tudor, silhouette, the skirts, Giant Reed, Skirts, seventeenth century, caricature, conjecture.

Defination from the web:
Farthingale is a term applied to any of several structures used under Western European women's clothing in the late fifteenth and sixteenth ... Chemise · Basque · Bustle · Crinoline · Farthingale · Hoop skirt · Liberty bodice · Pannier · Pantalettes · Petticoat · Pettipants · Waist cincher · Yếm ...