the.com/hoop skirt

means A stiff, bell-shaped underskirt held out by rings of whalebone, cane, or steel so a woman's dress could billow into a wide dome around her legs.

from English since the 1700s, simply joining 'hoop' (a circular band, from Old English hop) with 'skirt' (a lower garment, from Old Norse skyrta, the same root that gives us 'shirt'). The device itself has ancient ancestors — farthingales and panniers worked the same trick with different frames — but the hoop skirt proper boomed in the mid-1800s with steel-spring cages that let skirts reach enormous width without the heavy layers of petticoats they replaced. Fashion plates praised the airy swing; satirists and cartoonists had a field day with the logistics of doorways, carriages, and wind.