One watching language in vehicle carrying a communist west (9)
I believe the answer is:
moderator
'one watching language in vehicle carrying a communist west' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'watching language in vehicle carrying a communist west' is the wordplay.
I cannot quite see how this works, but
'watching' could be 'at' (e.g. watching a tennis match means you are at it) and 'at' is present in the answer.
'language' could be 'ro' (Ro is an example) and 'ro' is present in the leftover letters.
The remaining letters 'moder' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for moderator that I've seen before include "Presbyterian minister - superintendent of university examinations" , "Overseer of exam" , "One presides over a forum or debate" , "clerical figure" , "Site foreman" .)