Former pupil or student (7)
I believe the answer is:
alumnus
This clue is a double definition.
'former pupil' is the first definition.
(I've seen this before)
'student' is the second definition.
(I know that alumnus is a type of student)
(Other definitions for alumnus that I've seen before include "Old pupil" , "US college old boy" , "Former college pupil" , "Former pupil or student" , "Ex-pupil" .)