Flounce refers to a strip of fabric which is cut in a circle, cut on the bias or cut in a straight Line and gathered, which is attached to the edge of a garment, and ripples for femi nine effect.

A Flounce also refers to a wide ruffle; it t is a piece of material gathered and attached at one side, such as a large ruffle.

Moreover, a Flounce refers to a dress or skirt with a ruffle at the hemline, or one with multiple ruffled layers.
Other /More definition:
Flounce refers to a strip of decorative, usually gathered or pleated material attached by one edge, as on a garment or curtain or table cloth.

Moreover, a Flounce is an ornamental frill on a garment or tablecloth; a strip of pleated material used as a decoration or a trim.

A peplum is a short flounce added to the waist of a dress or jacket.