Rail coach carrying the French turned over business (10)
I believe the answer is:
balustrade
'rail' is the definition.
(balustrade is a kind of rail)
'coach carrying the french turned over business' is the wordplay.
'coach' becomes 'bus' ('bus' can be a synonym of 'coach'**).
'carrying' means one lot of letters goes inside another.
'the french' becomes 'la'.
'turned over' shows that the letters should be reversed in order.
'business' becomes 'trade' (trade is a kind of business).
'la' written backwards gives 'al'.
'bus' enclosing 'al' is 'balus'.
'balus'+'trade'='BALUSTRADE'
(Other definitions for balustrade that I've seen before include "feature of terrace, perhaps" , "Form of railing" , "Railing supported on pillars" , "Railing on stairs or balcony" , "Stair rail and its supports" .)