Uproar where French expression of amusement is faced by British (8)
I believe the answer is:
brouhaha
'uproar' is the definition.
(brouhaha is a kind of uproar)
'where french expression of amusement is faced by british' is the wordplay.
'where french' becomes 'ou' ('where' in French).
'expression of amusement' becomes 'haha'.
'is faced by' means one lot of letters go next to another.
'british' becomes 'br'.
'ou'+'haha'='ouhaha'
'ouhaha' put after 'br' is 'BROUHAHA'.
(Other definitions for brouhaha that I've seen before include "Stir" , "Noisy and overexcited reaction to something" , "Sensation" , "Noisy and critical response" , "Clamour" .)