One might believe this Indian died (5)
I believe the answer is:
creed
'one might believe this indian died' is the definition.
The definition and answer can be both related to communication as well as being singular nouns.
Maybe there's an association between them I don't understand?
'indian died' is the wordplay.
'indian' becomes 'cree' (Cree is an example).
'died' becomes 'd' (abbreviation next to the year of someone's death).
'cree'+'d'='CREED'
Can you help me to learn more?
(Other definitions for creed that I've seen before include "teleprinter" , "Set of beliefs or principles" , "Catechism" , "System of principles or beliefs" , "System of religious principles" .)