Remainder dwell permanently outside university (7)
I believe the answer is:
residue
'remainder' is the definition.
('residue' can be a synonym of 'remainder')
'dwell permanently outside university' is the wordplay.
'dwell permanently' becomes 'reside' (I've seen this before).
'outside' is an insertion indicator.
'university' becomes 'u'.
'reside' placed around 'u' is 'RESIDUE'.
(Other definitions for residue that I've seen before include "What is left over, remainder (7)" , "Remains to be seen" , "Deposit" , "Part remaining" , "What's left" .)