Shock beginning by the French (7)
I believe the answer is:
startle
'shock' is the definition.
(startling is a kind of shocking)
'beginning by the french' is the wordplay.
'beginning' becomes 'start' (start is a kind of beginning).
'by' means one lot of letters go next to another.
'the french' becomes 'le'.
'start'+'le'='STARTLE'
(Other definitions for startle that I've seen before include "Alarm suddenly" , "Alarm (someone)" , "Take unawares with rattles" , "Frighten suddenly" , "Cause shock/alarm" .)