Discreet college caught in unexpected fault after time (7)
I believe the answer is:
tactful
'discreet' is the definition.
('tactful' can be similar in meaning to 'discreet')
'college caught in unexpected fault after time' is the wordplay.
'college' becomes 'c'.
'caught in' indicates putting letters inside.
'unexpected' indicates anagramming the letters.
'after' is a charade indicator (letters next to each other).
'time' becomes 't'.
'fault' is an anagram of 'atful'.
'c' placed into 'atful' is 'actful'.
'actful' put after 't' is 'TACTFUL'.
(Other definitions for tactful that I've seen before include "Polite" , "Considerate for other's feelings" , "Delicate" , "Like diplomat" , "Discreet - diplomatic" .)