flounce 1 
(flouns)
(flouns)n.
A strip of decorative, usually gathered or pleated material attached by one edge, as on a garment or curtain.
tr.v. flounced, flounc·ing, flounc·es
To trim with a strip or strips of gathered or pleated material.
[Alteration of frounce, from Middle English, pleat, from Old French fronce, of Germanic origin; see sker-2 in the Appendix of Indo-European roots.]