Agreements to receive Sunday papers (9)
I believe the answer is:
treatises
'papers' is the definition.
The definition and answer can be both related to communication as well as being plural nouns.
Perhaps there's an association between them I don't understand?
'agreements to receive sunday' is the wordplay.
I cannot really see how this works, but
'sunday' could be 's' and 's' is located in the answer.
'agreements' could be 'treaties' (treaty is a kind of agreement) and 'treaties' is found in the remaining letters.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Another definition for treatises that I've seen is " Formal pieces of writing".)