One easing tension in crowd over French street uprising (7)
I believe the answer is:
masseur
'one easing tension' is the definition.
(I've seen this before)
'crowd over french street uprising' is the wordplay.
'crowd' becomes 'mass' (massing is a kind of crowding).
'over' is a charade indicator (letters next to each other).
'french street' becomes 'rue' (French for street or road).
'uprising' shows that the letters should be reversed in order.
'rue' reversed gives 'eur'.
'mass'+'eur'='MASSEUR'
'in' is the link.
(Other definitions for masseur that I've seen before include "One providing soothing treatment" , "Professional rubber?" , "One working in parlour" , "rubber found" , "One who kneads and strokes" .)