Great policeman (5)
I believe the answer is:
super
This clue is a double definition.
'great' is the first definition.
(both can mean excellent)
'policeman' is the second definition.
(short for superintendant)
(Other definitions for super that I've seen before include "Delightful" , "Smashing, terrific" , "Spiffing!" , "Brilliant" , "Fantastic" .)