"Citizen” of film (4)
I believe the answer is:
kane
'citizen of film' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for kane that I've seen before include "Great Orson Welles movie 'Citizen . . . .'" , "1941 cinematic citizen" , "Famous film by Orson Welles 'Citizen . . . .'" , "'Citizen . . . .', great film by Orson Welles" , "Orson Welles's film ` `Citizen ....' '" .)