Vulgar supporter upset female (4)
I believe the answer is:
naff
'vulgar' is the definition.
(both can mean tasteless)
'supporter upset female' is the wordplay.
'supporter' becomes 'fan' (fan is a kind of supporter).
'upset' is a reversal indicator.
'female' becomes 'f' (common abbreviation).
'fan' backwards is 'naf'.
'naf'+'f'='NAFF'
(Other definitions for naff that I've seen before include "socially awkward" , "Socially crass" , "Vulgarly tasteless" , "Vulgar, out of fashion or of poor quality" , "Vulgar and tasteless" .)