King Edward, well-informed (7)
I believe the answer is:
learned
'well-informed' is the definition.
(thesaurus)
'king edward' is the wordplay.
'king' becomes 'lear' (I've seen this before).
'edward' becomes 'ned'.
'lear'+'ned'='LEARNED'
(Other definitions for learned that I've seen before include "Gained knowledge" , "Acquired information, being well educated" , "Discovered, ascertained" , "Highly educated" , "Having great knowledge" .)