Circle forbidding perfume (5)
I believe the answer is:
odour
'perfume' is the definition.
(I've seen this before)
'circle forbidding' is the wordplay.
'circle' becomes 'O' (O is a circle).
'forbidding' becomes 'dour' (I've seen this in another clue).
'o'+'dour'='ODOUR'
(Other definitions for odour that I've seen before include "Perfume" , "Whiff" , "Aroma or fragrance" , "Smell; repute" , "Aroma, smell" .)