Prohibition a student finds trite (5)
I believe the answer is:
banal
'trite' is the definition.
(I've seen this in another clue)
'prohibition a student' is the wordplay.
'prohibition' becomes 'ban' (synonyms).
'student' becomes 'l' (as in L-plates for learner drivers).
'ban'+'a'+'l'='BANAL'
'finds' acts as a link.
(Other definitions for banal that I've seen before include "Overfamiliar through overuse" , "Old hat" , "'Dull, commonplace (5)'" , "Stock" , "lacking interest?" .)