Policeman, not soft, retrained for pit (4,4)
I believe the answer is:
coal mine
'pit' is the definition.
(pit for mining)
'policeman not soft retrained' is the wordplay.
'not' is a deletion indicator.
'soft' becomes 'p' (musical abbreviation for 'piano').
'retrained' indicates an anagram (train can mean to shape or direct a plant).
'policeman' with 'p' removed is 'oliceman'.
'oliceman' anagrammed gives 'COAL-MINE'.
'for' acts as a link.
(Other definitions for coal mine that I've seen before include "Pit" , "source of fuel" .)