Leader in Caribbean, a revolutionary sort (6)
I believe the answer is:
'leader' is the definition.
(I have seen 'Cuban leader' mean 'castro' so perhaps 'leader' could also mean 'castro')
'caribbean a revolutionary sort' is the wordplay.
'caribbean' becomes 'c' (this could be a standard abbreviation which I don't know about).
'revolutionary' indicates anagramming the letters.
'sort' is an anagram of 'stro'.
'in' is the link.
Can you help me to learn more?
(Other definitions for castro that I've seen before include "Fidel -, former Cuban leader" , "He's late" , "Cuban dictator" , "Fidel ......, Cuban chief" , "revolutionary leader" .)