Unenforced ordinance passed on to landlord (4,6)
I believe the answer is:
dead letter
'unenforced ordinance' is the definition.
The definition and answer can be both related to communication as well as being singular nouns.
Maybe there's a link between them I don't understand?
'passed on to landlord' is the wordplay.
'passed on' becomes 'dead' (I've seen this before).
'to landlord' becomes 'letter' (landlords let property).
'dead'+'letter'='DEAD-LETTER'
Can you help me to learn more?
(Other definitions for dead letter that I've seen before include "Ineffective rule" , "Unresponsive landlord" , "Itll not lead to prosecution" , "Law no longer enforced" , "no longer observed" .)