Refuse amorous advance at university (4,2)
I believe the answer is:
pass up
'refuse' is the definition.
(synonyms)
'amorous advance at university' is the wordplay.
'amorous advance' becomes 'pass' (I've seen this before).
'at university' becomes 'up'.
'pass'+'up'='PASS UP'
(Other definitions for pass up that I've seen before include "Showing neglect" , "Have nothing to do with" , "Refrain from seizing (an opportunity)" , "Refrain from taking an opportunity" , "Fail to take advantage of" .)