Rearing mountain lions making a university review … (3,2)
I believe the answer is:
sum up
'review' is the definition.
(thesaurus)
'rearing mountain lions making a university' is the wordplay.
I cannot really understand how this works, but
'mountain' could be 'm' (geographical abbreviation) and 'm' is located in the answer.
'university' could be 'u' (abbreviation for university) and 'u' is found within the answer.
The remaining letters 'sup' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
(Other definitions for sum up that I've seen before include "Recapitulate (in court)" , "Review evidence at end of a case" , "What judge does for jury before they retire to consider verdict" , "Make final precis of evidence" , "Money more than before" .)