Pub turned over at first by the French mob (6)
I believe the answer is:
rabble
'mob' is the definition.
('rabble' can be a synonym of 'mob')
'pub turned over at first by the french' is the wordplay.
'pub' becomes 'bar' (I've seen this before).
'turned over' shows that the letters should be reversed in order.
'at first' says to take the initial letters.
'the french' becomes 'le'.
The first letter of 'by' is 'b'.
'bar' in reverse letter order is 'rab'.
'rab'+'b'+'le'='RABBLE'
(Other definitions for rabble that I've seen before include "A mob of riffraff" , "Disorderly crowd or mob" , "Leaderless mob" , "Person who stirs up feeling of mob" , "Person manipulating mob's passion" .)