Policeman to stun rare and excellent thing (5-7)
I believe the answer is:
bobby-dazzler
'thing' is the definition.
(I have seen 'Attractive thing' mean 'bobby dazzler' so perhaps 'thing' could also mean 'bobby dazzler')
'policeman to stun rare and excellent' is the wordplay.
I cannot really understand how this works, but
'policeman' could be 'bobby' (bobby is a kind of policeman) and 'bobby' is present in the answer.
'rare' could be 'r' (listed by Oxford Dictionary of Abbreviations) and 'r' is located in the answer.
The remaining letters 'dazzle' 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 bobby-dazzler that I've seen before include "Strikingly impressive person or thing" , "Really attractive person" , "Strikingly attractive woman" , "Stunning girl" .)