France is French -- nothing about garnish (7)
I believe the answer is:
festoon
'garnish' is the definition.
(both can mean to decorate or adorn something)
'france is french nothing about' is the wordplay.
'france' becomes 'f'.
'is french' becomes 'est' ('is' in French).
'nothing' becomes 'O' (O resembles 0).
'about' becomes 'on' (as in a book 'on' a certain topic).
'f'+'est'+'o'+'on'='FESTOON'
(Other definitions for festoon that I've seen before include "Decoration" , "swag" , "Decorative chain" , "Ornamental chain/garland" , "So often (anag.)" .)