In name, a link (6)
I believe the answer is:
hyphen
'a link' is the definition.
The answer and definition can be both related to communication as well as being singular nouns.
Maybe there's a link between them I don't understand?
'in name' is the wordplay.
I cannot really see how this works, but
'name' could be 'hy' and 'hy' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for hyphen that I've seen before include "Sign linking words" , "A horizontal word joiner" , "Mark joining two words" , "It joins two words" , "Stroke between syllables or words" .)