An underskirt is a garment worn underneath a dress or skirt to give it extra volume, shape, or coverage. Think of it as a hidden helper that makes the outer skirt look fuller and more dramatic.

In historical fashion, underskirts were essential. Victorian women wore multiple underskirts, sometimes layered with stiff materials like horsehair, to create those wide, bell-shaped silhouettes you see in old paintings. Ballet dancers wear special underskirts called tutus that stick straight out, creating that classic ballerina look. Wedding dresses often have underskirts with hoops or stiff netting to make the gown billow out elegantly.

The word can also refer to a simple slip: a smooth, lightweight underskirt that prevents the outer skirt from clinging to your legs or becoming see-through. While most modern clothing doesn't require underskirts, they're still used in formal wear, costumes, and traditional clothing around the world. When you see a flamenco dancer's skirt swirling dramatically or a bride's gown flowing down the aisle, there's likely an underskirt beneath, doing the important work of creating that beautiful shape.