At university, group is disturbed (5)
I believe the answer is:
upset
'is disturbed' is the definition.
(synonyms)
'at university group' is the wordplay.
'at university' becomes 'up' (to 'come up' is to arrive for term, e.g. at Oxford).
'group' becomes 'set' (both can mean a collection).
'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" .)