Soldier joining some of the French marches (7)
I believe the answer is:
parades
'marches' is the definition.
(parading is a kind of marching)
'soldier joining some of the french' is the wordplay.
'soldier' becomes 'para' (para is a kind of soldier).
'joining' is a charade indicator (letters next to each other).
'some of the french' becomes 'des'.
'para'+'des'='PARADES'
(Other definitions for parades that I've seen before include "Displays" , "Cavalcades" .)