Frill — flounce (8)
I believe the answer is:
I believe this is a double definition.
'frill' is the first definition.
(I know that frill can be written as furbelow)
'flounce' is the second definition.
(I know that flounce can be written as furbelow)
(Other definitions for furbelow that I've seen before include "decoration for skirt, one gathered" , "Ornamental trim" , "Bit of skirt" , "superfluous ornament!" , "Fringe" .)