A sad teen wandering round university, sickened (9)
I believe the answer is:
nauseated
'sickened' is the definition.
('nauseate' can be a synonym of 'sicken')
'a sad teen wandering round university' is the wordplay.
'wandering' indicates an anagram.
'round' indicates putting letters inside.
'university' becomes 'u'.
'a'+'sad'+'teen'='asadteen'
'asadteen' with letters rearranged gives 'naseated'.
'naseated' placed around 'u' is 'NAUSEATED'.
(Other definitions for nauseated that I've seen before include "Sickened" , "Revolted" , "Disgusted" .)