In Scotland, it has its regional side (3)
I believe the answer is:
tay
'regional side' is the definition.
The answer and definition can be both related to communication as well as being singular nouns.
Maybe there's an association between them I don't understand?
'in scotland it has its' is the wordplay.
I cannot quite understand how this works, but
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is found in the answer.
The remaining letters 'ay' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for tay that I've seen before include "Scottish river and firth" , "The - Bridge Disaster (McGonagall)" , "Scottish river in Katayama?" , "Longest river of Scotland" , "Scotland's longest river" .)