Class outside university is place for discussion (5)
I believe the answer is:
forum
'place for discussion' is the definition.
(I've seen this in another clue)
'class outside university' is the wordplay.
'class' becomes 'form' (synonyms).
'outside' indicates putting letters inside (some letters go outside others).
'university' becomes 'U' (abbreviation as in UMass).
'form' enclosing 'u' is 'FORUM'.
'is' is the link.
(Other definitions for forum that I've seen before include "Place to discuss ideas" , "old square" , "Internet message board" , "A meeting to exchange views" , "Public meeting-place for open discussion" .)