Busy? Not working, with time for fun principally! (9)
I believe the answer is:
detective
'busy?' is the definition.
(busy can informally mean a police officer)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for detective that I've seen before include "Investigating policeman" , "such as Chesterton's father" , "Sleuth" , "Criminal investigator" , "police officer" .)