Great work, English Chambers (4)
I believe the answer is:
epos
'great work english' is the definition.
The definition and answer can be both related to communication as well as being singular nouns.
Maybe you can see a link between them that I can't see?
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for epos that I've seen before include "One has many lines" , "Things sold here" , "body of poetry" , "Epic poem; electronic point of sale (abbrev.)" , "Verse" .)