Policeman arranged toil for fellow flier (7)
I believe the answer is:
copilot
'flier' is the definition.
(copilot is a kind of flier)
'policeman arranged toil for fellow' is the wordplay.
'policeman' becomes 'p' (this might be a standard abbreviation which I don't know about).
'arranged' indicates an anagram (letters rearranged).
'for' says to put letters next to each other (I've seen this in other clues).
'fellow' becomes 'co' (eg a co-worker is a fellow worker).
'toil' is an anagram of 'ilot'.
'p'+'ilot'='pilot'
'pilot' after 'co' is 'COPILOT'.
Can you help me to learn more?
(Other definitions for copilot that I've seen before include "Airliner crew member" , "Second-in-command of aeroplane" .)