Speak unfavourably about traffic outside fronts of university colleges (7)
I believe the answer is:
traduce
'speak unfavourably' is the definition.
(to traduce is to speak badly about)
'traffic outside fronts of university colleges' is the wordplay.
'traffic' becomes 'trade' (traffic can mean illegal trade).
'outside' means one lot of letters goes inside another.
'fronts of' indicates taking the first letters.
The first letters of 'university colleges' is 'uc'.
'trade' placed around 'uc' is 'TRADUCE'.
'about' acts as a link.
(Other definitions for traduce that I've seen before include "Tell lies about (someone)" , "Calumniate" , "Slander - misrepresent" , "Misrepresent in unfavourable way" , "abuse" .)