Such a script would communicate nothing (9)
I believe the answer is:
illegible
'such' is the definition.
Both the definition and answer are adjectives. Maybe you can see a link between them that I can't see?
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for illegible that I've seen before include "Not capable of being read" , "Hard to read" , "Unreadable" , "Impossible to read" , "Not easily read" .)