The writer's prudish, having exposed adult book licence (10)
I believe the answer is:
imprimatur
'book licence' is the definition.
The answer and definition can be both related to communication as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'the writer's prudish having exposed adult' is the wordplay.
'the writer's' becomes 'im' (both could mean 'the crossword setter is').
'prudish' becomes 'prim' (synonyms).
'having' is a charade indicator (letters next to each other).
'exposed' says to take the centre (outside letters removed).
'adult' becomes 'mature' (similar in meaning).
The centre of 'mature' is 'atur'.
'im'+'prim'+'atur'='IMPRIMATUR'
Can you help me to learn more?
(Other definitions for imprimatur that I've seen before include "church licence" , "Church approval" .)