One's old school or university (4,5)
I believe the answer is:
alma mater
I believe this is a double definition.
'one's old school' is the first definition.
(I've seen this in another clue)
'university' is the second definition.
(thesaurus)
(Other definitions for alma mater that I've seen before include "old college" , "One's old place of learning" , "Alert mama to the old school" , "One's old university" , "Where one learned" .)