An outcome which makes ma a gran! (7)
I believe the answer is:
anagram
'an outcome which' is the definition.
The definition and answer can be both related to communication as well as being singular nouns.
Maybe you can see an association between them that I can't see?
'makes ma a gran' is the wordplay.
'makes' is an anagram indicator.
'ma'+'a'+'gran'='maagran'
'maagran' anagrammed gives 'ANAGRAM'.
Can you help me to learn more?
(Other definitions for anagram that I've seen before include "Argue the point" , ""Angered" of "enraged", perhaps?" , "type of clue" , "Cruciverbal jumble" , "Shuffling of letters" .)