It's silly but favoured before an Oriental (5)
I believe the answer is:
inane
'it's silly' is the definition.
(thesaurus)
'favoured before an oriental' is the wordplay.
'favoured' becomes 'in' (I've seen this in other clues).
'before' is a charade indicator (letters next to each other).
'oriental' becomes 'e'.
'in'+'an'+'e'='INANE'
'but' is the link.
(Other definitions for inane that I've seen before include "Fatuous, vacuous" , "Empty" , "Annie (anag.)" , "Lacking meaning" , "Foolish, fatuous" .)