World leaders that shout and argue have become sour (6)
I believe the answer is:
saturn
'world leaders that shout' is the definition.
'Saturn' can be an answer for 'world' (Saturn is another planet). I'm not sure about the remainder of the definition.
'argue have become sour' is the wordplay.
'argue have' becomes 'sa' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'become sour' becomes 'turn' (I've seen this in another clue).
'sa'+'turn'='SATURN'
'and' acts as a link.
Can you help me to learn more?
(Other definitions for saturn that I've seen before include "The second largest planet" , "Turn as a planet" , "Giant planet" , "tried to pass vessel" , "Roman god - gas giant" .)