Drug dealer, Argentine revolutionary on film (7)
I believe the answer is:
chemist
'drug dealer' is the definition.
(I've seen this before)
'argentine revolutionary on film' is the wordplay.
'argentine revolutionary' becomes 'che' (Che Guevara the Marxist revolutionary).
'on' is a charade indicator (letters next to each other).
'film' becomes 'mist' (I've seen this in other clues).
'che'+'mist'='CHEMIST'
(Other definitions for chemist that I've seen before include "Medicine dispenser" , "drug dealer" , "Shop for drugs" , "Pharmacist, apothecary" , "He dispenses prescriptions" .)