Shoots back to a little bar (5)
I believe the answer is:
serif
'a little bar' is the definition.
The definition and answer can be both related to communication as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'shoots back' is the wordplay.
'shoots' becomes 'fires' (firing is a kind of shooting).
'back' says the letters should be written backwards.
'fires' backwards is 'SERIF'.
'to' is the link.
Can you help me to learn more?
(Other definitions for serif that I've seen before include "Small line used in printing type" , "Decorative part of font" , "Brazil port" , "Feature of some typefaces" , "Line on written letters" .)