VIP doctor joins German university student (5)
I believe the answer is:
mogul
'vip' is the definition.
(thesaurus)
'doctor joins german university student' is the wordplay.
'doctor' becomes 'mo' (medical officer).
'joins' is a charade indicator (letters next to each other).
'german' becomes 'g' (abbreviation).
'university' becomes 'U' (abbreviation as in UMass).
'student' becomes 'L' (as in L-plates for learner drivers).
'mo'+'g'+'u'+'l'='MOGUL'
(Other definitions for mogul that I've seen before include "Magnate (from India?)" , "Magnate; mound of hard snow on a ski slope" , "Indian emperor - important person" , "Very wealthy or powerful business person" , "Big cheese - mound of hard snow on a ski slope" .)