An illustration of "crinoline." Whenever I've read that word, I've always assumed the reference was to the fabric - a stiff fabric "with a weft of horse-hair and a warp of cotton or linen thread." Further reading of the Wiki entry reveals that the "crinoline" can also refer to the steel structure underneath the skirt.
The Wiki entry explains all, and leads to related links for the farthingale (Queen Elizabeth I), the pannier (Marie Antoinette), and the more familiar bustle (your grandmother).
"Crinoline" etymology from a combination of the Latin/French words for horse "crinis/crin" + linen "linum/lin."
(Image credit to e-l-i-s-e. Wikipedia calls the sequence of five photos from which this is taken a "caricature," without further explication.)