Charm of French anthem (7)
I believe the answer is:
enchant
'charm' is the definition.
(enchanting is a kind of charming)
'of french anthem' is the wordplay.
'of' indicates a hidden word.
'ENCHANT' can be found hidden inside 'french anthem'.
(Other definitions for enchant that I've seen before include "Fascinate - delight" , "Delight, cast spell over" , "Appeal" , "Bewitch, charm" , "Beguile" .)