No Edwardian is very well known (5)
I believe the answer is:
noted
'very well known' is the definition.
'noted' can be an answer for 'known' (similar in meaning). I am not sure about the 'very well' bit.
'no edwardian' is the wordplay.
'edwardian' becomes 'ted' (I am not sure about this - if you are sure you should believe this answer much more).
'no'+'ted'='NOTED'
'is' acts as a link.
Can you help me to learn more?
(Other definitions for noted that I've seen before include "remarked upon" , "Observed or took account of" , "Scores like this" , "Well known; registered" , "Like music" .)