At university, quiet group gets troubled (5)
I believe the answer is:
'troubled' is the definition.
(similar in meaning)
'at university quiet group' is the wordplay.
'at' says to put letters next to each other.
'university' becomes 'u' (abbreviation for university).
'quiet' becomes 'p' (music symbol for 'piano', ie soft or quiet).
'group' becomes 'set' (both can mean a collection).
'u'+'p' is 'up'.
'gets' is the link.
(Other definitions for upset that I've seen before include "Disordered - unexpected defeat" , "Disturb - spoil" , "Trouble" , "Unhappy - unexpected defeat" , "Spilt - annoyed" .)