What is a "polonaise"?

A polonaise is a historical women's garment that was fashionable in the 18th and 19th centuries and inspired by Polish national costume. The dress consists of a fitted bodice and a gathered or pleated skirt, typically worn over an underskirt or petticoat. The defining feature of a polonaise is the gathered and draped fabric at the back of the dress, which forms a train. The polonaise was originally a military dress uniform of Polish origin, but over time it evolved into a fashionable dress for women. The style was revived in the mid-19th century and remained popular throughout the Victorian era.