They regard six of the Roman jugs (7)

I believe the answer is:
viewers
'they regard' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'six of the roman jugs' is the wordplay.
I cannot really understand how this works, but
'six' could be 'vi' (Roman numerals) and 'vi' is located in the answer.
'jugs' could be 'ewers' (ewer is a type of jug) and 'ewers' is located in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for viewers that I've seen before include "spectators" , "TV addicts" .)