Old policeman used in the kitchen? (6)
I believe the answer is:
peeler
I believe this clue is a double definition.
'old policeman' is the first definition.
(historical nickname for a policeman)
'used in the kitchen?' is the second definition.
(vegetable peeler)
(Other definitions for peeler that I've seen before include "Devious type" , "Potato skinner" , "Old copper" , "Very old English cop, or spud scraper" , "Kitchen knife" .)