Degenerate stealing traditional oriental flower-shaped decoration (7)
I believe the answer is:
rosette
'decoration' is the definition.
(rosette is a kind of decoration)
'degenerate stealing traditional oriental' is the wordplay.
'degenerate' becomes 'rot' (rotting is a kind of degenerating).
'stealing' indicates putting letters inside.
'traditional' becomes 'set' (I can't justify this - if you can you should give a lot more credence to this answer).
'oriental' becomes 'e'.
'rot' placed around 'set' is 'rosett'.
'rosett'+'e'='ROSETTE'
'flower-shaped' acts as a link.
This may not be correct. It may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for rosette that I've seen before include "Colourful decoration worn by supporters" , "Prizewinner's decoration" , "collection of ribbons" , "Horse show award" , "sign of a champion?" .)