Turns up, Arab prince is cold, crude and in violation of the Geneva Convention (3,5)
I believe the answer is:
war crime
'violation of the geneva convention' is the definition.
The answer and definition can be both acts as well as being singular nouns.
Maybe there's a link between them I don't understand?
'turns up arab prince is cold crude' is the wordplay.
'turns up' says the letters should be written in reverse.
'arab prince' becomes 'emir' (I've seen this before).
'is cold' becomes 'c' (eg on taps).
'crude' becomes 'raw' ('raw' can be a synonym of 'crude').
'emir'+'c'+'raw'='emircraw'
'emircraw' backwards is 'WAR CRIME'.
'and in' acts as a link.
Can you help me to learn more?
(Other definitions for war crime that I've seen before include "Breach of international law governing conflict" , "Offence during conflict" , "Act of genocide" , "Illegal act in a conflict" , "Violation of accepted rules of conflict" .)