Which of these was designed to hold out a woman's skirt?
Correct answer: Crinoline

Kat
Wonder if this was to keep the gentlemen at arm's length...and then some?!

luckycatfay
MickWarts41, bustle was at the back of a dress over the bottom.

Castra
Unreal Neil.,
Nope, a bolster is a long pillow that goes under the normal pillows on a bed.
My parents had one on their bed.

Unreal Neil.
A bolster was worn beneath a petticoat.