Get the better of idiot joining higher education establishment (6)
I believe the answer is:
outwit
'get the better of' is the definition.
(both can mean to outsmart)
'idiot joining higher education establishment' is the wordplay.
'idiot' becomes 'twit' (I've seen this in other clues).
'joining' is a charade indicator (letters next to each other).
'higher education establishment' becomes 'OU' (Open University).
'twit' after 'ou' is 'OUTWIT'.
(Other definitions for outwit that I've seen before include "Deceive through greater ingenuity" , "To fox" , "To appear smarter" , "Surpass in ingenuity" , "Show more ingenuity than" .)