Smashed by the French activity (6)
I believe the answer is:
bustle
'activity' is the definition.
(I've seen this before)
'smashed by the french' is the wordplay.
'smashed' becomes 'bust' (bust can mean broken or smashed).
'by' says to put letters next to each other.
'the french' becomes 'le' ('the' in French).
'bust'+'le'='BUSTLE'
(Other definitions for bustle that I've seen before include "Flurry, fuss" , "Hurry, scramble" , "Energetic activity" , "Sublet (anag)" , "A show of hurrying, or old skirt back padding" .)