Something pretty exciting to the cockney, we hear (5)
I believe the answer is:
frill
If this is the answer, I'm afraid I cannot explain it.
Can you help me to learn more?
(Other definitions for frill that I've seen before include "Superfluous ornament; ruffle" , "Maybe superfluous piece of adornment" , "Trim" , "Shared feature of Mr Punch, Richard III" , "Extra embellishment" .)