By-law puts half of it into artillery (9)
I believe the answer is:
ordinance
'by-law' is the definition.
The answer and definition can be both related to communication as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'half of it into artillery' is the wordplay.
'half of it' becomes 'i' (I am not sure about this - if you are sure you should believe this answer much more).
'into' is an insertion indicator.
'artillery' becomes 'ordnance' (synonyms).
'i' going into 'ordnance' is 'ORDINANCE'.
'puts' is the link.
Can you help me to learn more?
(Other definitions for ordinance that I've seen before include "Bill" , "Bye-law of a city government" , "planning" , "law" , "Regulation" .)