Director Welles (5)
I believe the answer is:
'director welles' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for orson that I've seen before include ". . . . . Welles, creator of film ''Citizen Kane''" , "-- Welles, US director" , "-- Welles, director/actor" , "_____ Welles, director and star of "Citizen Kane"" , "-- Welles, film producer" .)