Smart leader of The Police (5)
I believe the answer is:
sting
'smart' is the definition.
(both can mean to burn or hurt)
'leader of the police' is the wordplay.
I cannot really see how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is present in the answer.
The remaining letters 'sing' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for sting that I've seen before include "Tingle sharply" , "Con: leader singer of Police" , "English musician, b. 1951 -- a sudden pain" , "Smart - cheat" , "Sudden pain - swindle" .)