Location reference after chapter and verse (8)
I believe the answer is:
postcode
'location reference' is the definition.
The answer and definition can be both related to communication as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'after chapter and verse' is the wordplay.
'after' becomes 'post' (prefix meaning after, eg post-war).
'chapter' becomes 'c' (abbreviation).
'and' means one lot of letters go next to another.
'verse' becomes 'ode' (ode is a type of poem or verse).
'post'+'c'+'ode'='POSTCODE'
Can you help me to learn more?
(Other definitions for postcode that I've seen before include "Mail sorting help" , "Indication of area in address" , "Part of address to aid sorting" , "Eg, E ninety eight one TT" , "Eg, E-Nine-Eight One-T-T" .)