Be too clever for old university idiot (6)
I believe the answer is:
outwit
'be too clever for' is the definition.
(I've seen this before)
'old university idiot' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'university' becomes 'u'.
'idiot' becomes 'twit' (I've seen this in other clues).
'o'+'u'+'twit'='OUTWIT'
(Other definitions for outwit that I've seen before include "Gull" , "Be too clever for, get the better of" , "Defeat by superior ingenuity" , "Be too smart for, defeat" , "Get the better of by being smarter" .)