Class holds university debate (5)
I believe the answer is:
forum
'debate' is the definition.
(thesaurus)
'class holds university' is the wordplay.
'class' becomes 'form' (form class is a kind of class).
'holds' is an insertion indicator.
'university' becomes 'u'.
'form' placed around 'u' is 'FORUM'.
(Other definitions for forum that I've seen before include "Place of assembly for the people in ancient Greece" , "Place where public meeting or discussion is held" , "place for debate" , "Place for open discussion" , "Roman meeting place" .)