Note about university setback (5)
I believe the answer is:
delay
'setback' is the definition.
(thesaurus)
'note about university' is the wordplay.
'note' becomes 'd' (musical note).
'about' is a reversal indicator.
'university' becomes 'Yale' (Yale is an example).
'yale' back-to-front is 'elay'.
'd'+'elay'='DELAY'
(Other definitions for delay that I've seen before include "Temporise" , "Hold back" , "hold-up of train?" , "Postpone, defer" , "Stoppage" .)