Edison leaving out of cowardliness is hard to read (6)
I believe the answer is:
scrawl
'read' is the definition.
The definition and answer can be both related to communication as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for scrawl that I've seen before include "Scribbled writing" , "Illegible handwriting" , "Illegible hand" , "Write hastily" , "Messy drawing, possibly" .)