Cash in fancy jewellery (6)
I believe the answer is:
chains
'jewellery' is the definition.
(a chain is a type of a jewellery)
'cash in fancy' is the wordplay.
'fancy' is an anagram indicator.
'cash'+'in'='cashin'
'cashin' with letters rearranged gives 'CHAINS'.
(Other definitions for chains that I've seen before include "Restriction" , "help to pull?" , "Restraints; series" , "Cash in (anag)" , "Fetters" .)