Idle cop somehow to turn back his support? (6,3)
I believe the answer is:
police dog
'his support?' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'idle cop somehow to turn back' is the wordplay.
'somehow' indicates anagramming the letters.
'to turn' becomes 'go' (a person's move in a board game).
'back' says the letters should be written backwards.
'go' back-to-front is 'og'.
'idle'+'cop'='idlecop'
'idlecop' anagrammed gives 'policed'.
'policed'+'og'='POLICE DOG'
(Other definitions for police dog that I've seen before include "busy helper" , "Canine for the boys in blue" , "Drug hunter" , "one taking lead in war on crime" , "maybe I do a lot of sniffing" .)