Trips once arranged for police officer (9)
I believe the answer is:
inspector
'police officer' is the definition.
(inspector is a kind of police officer)
'trips once arranged' is the wordplay.
'arranged' is an anagram indicator (letters rearranged).
'trips'+'once'='tripsonce'
'tripsonce' anagrammed gives 'INSPECTOR'.
'for' acts as a link.
(Other definitions for inspector that I've seen before include "reviewer" , "Morse" , "bluebottle!" , "senior cop" , "Person whose job it is to examine efficiency as in schools" .)