Amuse the French on credit (6)
I believe the answer is:
tickle
'amuse' is the definition.
(thesaurus)
'the french on credit' is the wordplay.
'the french' becomes 'le'.
'on' is a charade indicator (letters next to each other).
'credit' becomes 'tick' (I've seen this before).
'le' put after 'tick' is 'TICKLE'.
(Other definitions for tickle that I've seen before include "Touch lightly to cause laughter" , "Amuse; make tingle" , "Make to laugh with finger movement" , "Excite with fingertips" , "Stimulate" .)