The Parisian, extremely supercilious? To a smaller extent (4)
I believe the answer is:
less
'a smaller extent' is the definition.
(I've seen this in other clues)
'the parisian extremely supercilious?' is the wordplay.
'the parisian' becomes 'le' (definite article in French).
'extremely' says to hollow out the word (remove centre letters).
'supercilious' with its centre taken out is 'ss'.
'le'+'ss'='LESS'
'to' acts as a link.
(Other definitions for less that I've seen before include "Smaller in amout or degree" , "inferior" , "more, as they say" , "A smaller amount" , "See 12" .)