Employment of university philosopher (5)
I believe the answer is:
usage
'employment' is the definition.
(synonyms)
'university philosopher' is the wordplay.
'university' becomes 'U' (abbreviation for university).
'philosopher' becomes 'sage' (sage can mean a wise person).
'u'+'sage'='USAGE'
'of' is the link.
(Other definitions for usage that I've seen before include "Interest of old" , "Habit" , "management" , "Treatment, practice" , "Way of employing" .)