Onetime Argentine leader (5)
I believe the answer is:
peron
'onetime argentine leader' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for peron that I've seen before include "Former Argentine leader" , "Argentinian dictator, 1946-55" , "Prone to being an Argentine president" , "Argentinian president, Evita his wife" , "Former Argentinian leader" .)