Duke holding place at Cambridge (7)
I believe the answer is:
downing
'place at cambridge' is the definition.
(college at the University of Cambridge )
'duke holding' is the wordplay.
'duke' becomes 'd'.
'holding' becomes 'owning'.
'd'+'owning'='DOWNING'
(Other definitions for downing that I've seen before include "and 17: Thoroughfare of government" , "Street that houses British P.M." , "Drinking" , "College of Cambridge" .)