Bell or whistle (5)
I believe the answer is:
frill
'bell or whistle' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for frill that I've seen before include "Unnecessary embellishment" , "Gathered strip as a trimming" , "Ruff, adornment" , "Pleated strip of cloth trimming or an unnecessary extra" , "A decorative gathering of fabric" .)