Rain is an upset for Middle East people (8)
I believe the answer is:
iranians
'middle east people' is the definition.
The definition and answer can be both related to communication as well as being plural nouns.
Maybe you can see an association between them that I can't see?
'rain is an upset' is the wordplay.
'upset' indicates an anagram.
'rain'+'is'+'an'='rainisan'
'rainisan' anagrammed gives 'IRANIANS'.
'for' is the link.
Can you help me to learn more?
(Other definitions for iranians that I've seen before include "Nationality of Tehran's citizens" , "Nationality of citizens of Tehran" .)