Erudite King Edmund (7)
I believe the answer is:
learned
'erudite' is the definition.
(synonyms)
'king edmund' is the wordplay.
'king' becomes 'lear' (Shakespeare's King Lear).
'edmund' becomes 'ned' (Ned can be short for Edmund).
'lear'+'ned'='LEARNED'
(Other definitions for learned that I've seen before include "Discovered, ascertained" , "Highly educated" , "Educated, scholarly" , "Gained knowledge" , "Acquired information, being well educated" .)