Drives off in reverse clutching last piece of jewellery (7)
I believe the answer is:
sleeper
'jewellery' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe you can see a link between them that I can't see?
'drives off in reverse clutching last piece' is the wordplay.
'drives off' becomes 'repels' ('repel' can be a synonym of 'drive off').
'in reverse' says the letters should be written in reverse.
'clutching' is an insertion indicator.
'last piece' becomes 'e' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'repels' written backwards gives 'sleper'.
'sleper' going around 'e' is 'SLEEPER'.
'of' is the link.
Can you help me to learn more?
(Other definitions for sleeper that I've seen before include "Timber beam" , "Inactive spy" , "Possibly ring" , "Train with berths" , "An overnight train?" .)