Piece of jewellery couple hired (8)
I believe the answer is:
bracelet
'piece of jewellery' is the definition.
(I've seen this before)
'couple hired' is the wordplay.
'couple' becomes 'brace' ('brace' can be a synonym of 'couple'**).
'hired' becomes 'let' (I've seen this before).
'brace'+'let'='BRACELET'
(Other definitions for bracelet that I've seen before include "Item of jewellery found in Crete lab" , "Ornamental band worn on wrist" , "Arm band" , "Personal ornament" , "Rebel cat (anag.)" .)