The quiet one is novel (8)
I believe the answer is:
american
'novel' is the definition.
The answer and definition can be both related to communication as well as being singular nouns.
Perhaps you can see a link between them that I don't see?
'the quiet one' is the wordplay.
I cannot quite understand how this works, but
'one' could be 'me' (a setter might use 'one' to humourously mean 'me') and 'me' is present in the answer.
This explanation may well be incorrect...
'is' acts as a link.
Can you help me to learn more?
(Other definitions for american that I've seen before include "From across the pond" , "Game played on a gridiron" , "Sherman, for example" , "from Hollywood?" , "Nationality of Yankee Doodle Dandy" .)