Smart fellow in Zurich maybe sounding drunk (5)
I believe the answer is:
swish
'smart' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
(Other definitions for swish that I've seen before include "Extravagant" , "Smart; stylish" , "Elegant" , "Impressively smart" , "Impressively fashionable" .)