At university, group is disturbed (5)
I believe the answer is:
upset
'is disturbed' is the definition.
('upset' can be a synonym of 'disturbed')
'at university group' is the wordplay.
'at university' becomes 'up'.
'group' becomes 'set' (set is a kind of group).
'up'+'set'='UPSET'
(Other definitions for upset that I've seen before include "Overturn or discompose" , "Overturn or unsettle" , "Distraught" , "Disturb the balance or stability of" , "Surprise - distress" .)