Symbol of French corruption (6)
I believe the answer is:
device
'symbol' is the definition.
(thesaurus)
'of french corruption' is the wordplay.
'of french' becomes 'de' ('of' in French).
'corruption' becomes 'vice' (moral corruption).
'de'+'vice'='DEVICE'
(Other definitions for device that I've seen before include "Trick; heraldic design" , "Plan, scheme, trick" , "Appliance; scheme" , "something mechanical?" , "Scheme, trick; item of equipment" .)