The French girl, sensitive to money (5,6)
I believe the answer is:
legal tender
'money' is the definition.
(I've seen this before)
'the french girl sensitive' is the wordplay.
'the french' becomes 'le' ('the' in French).
'girl' becomes 'gal' (synonyms).
'sensitive' becomes 'tender' (synonyms).
'le'+'gal'+'tender'='LEGAL TENDER'
'to' acts as a link.
(Other definitions for legal tender that I've seen before include "Valid currency" , "Good money" , "Money which must be accepted as payment" , "Official currency" , "Unrefusable form of currency" .)