hoop skirt
shaped framework of reed, cane, or steel, used to support women's dresses in the fashionable silhouette of a particular period
crinoline
petticoat
farthingale
supports in the form of hoops or padded rolls, worn beneath a skirt to add fullness, worn in the 16th and 17th centuries
pannier
hoopskirt or open framework to extend a skirt's width at the sides