Reinforce argument at university (4,2)
I believe the answer is:
beef up
'reinforce' is the definition.
(thesaurus)
'argument at university' is the wordplay.
'argument' becomes 'beef' (I've seen this before).
'at university' becomes 'up'.
'beef'+'up'='BEEF UP'
(Other definitions for beef up that I've seen before include "Add strength to" , "Give added strength" , "Gain muscle" , "message poor meat-eaters won't want to hear?" , "Strengthen with cow meat?" .)