Wealthy leader's funny dog caught traitor (9)
I believe the answer is:
plutocrat
'wealthy leader's' is the definition.
(someone deriving power from immense wealth)
'funny dog caught traitor' is the wordplay.
'funny dog' becomes 'pluto' (I have seen 'animated dog' mean 'pluto' so perhaps 'dog' could also mean 'pluto'. I am not sure about the 'funny' bit.).
'caught' becomes 'c' (cricket abbreviation).
'traitor' becomes 'rat' (I've seen this before).
'pluto'+'c'+'rat'='PLUTOCRAT'
Can you help me to learn more?
(Other definitions for plutocrat that I've seen before include "Richest man" , "powerful rich type" , "One could bankroll the movie?" , "Wealthy man" , "Person who derives power from wealth" .)