Handwriting used in screenplay (6)
I believe the answer is:
script
I believe this is a double definition.
'handwriting' is the first definition.
(I know that handwriting can be written as script)
'screenplay' is the second definition.
(I've seen this in another clue)
'used in' acts as a link.
(Other definitions for script that I've seen before include "Orginal document" , "Screenplay" , "Form of text" , "Calligraphy" , "Performance text" .)