Planet's south leading a revolution (6)
I believe the answer is:
saturn
'planet's' is the definition.
(Saturn is an example)
'south leading a revolution' is the wordplay.
'leading' suggests taking the first letters.
'revolution' becomes 'turn' (I've seen this before).
The initial letter of 'south' is 's'.
's'+'a'+'turn'='SATURN'
(Other definitions for saturn that I've seen before include "Massive body ringed" , "deity" , "Solar system planet" , "tried to pass vessel" , "Planet with concentric rings" .)