Turf war? (7,6)
I believe the answer is:
pitched battle
'turf war?' is the definition.
The definition and answer can be both acts as well as being singular nouns.
Maybe there's an association between them I don't understand?
'turf war?' is the wordplay.
'turf' becomes 'pitched' (I can't justify this - if you can you should give a lot more credence to this answer).
'war?' becomes 'battle' (I've seen this before).
'pitched'+'battle'='PITCHED BATTLE'
Can you help me to learn more?
(Other definitions for pitched battle that I've seen before include "Culloden (1746), for example" , "Prearranged skirmish" , "Violent confrontation" , "Prearranged military engagement" , "Furious combat" .)