Wonderful policeman (5)
I believe the answer is:
super
I believe this is a double definition.
'wonderful' is the first definition.
(I've seen this in another clue)
'policeman' is the second definition.
(short for superintendant)
(Other definitions for super that I've seen before include "Exceptionally good" , "of high quality" , "Wicked" , "Prefix meaning over-excellent!" , "Prefix meaning over or extremely" .)