Dim feller now surprisingly knowledgeable (4-8)

I believe the answer is:

well-informed

'knowledgeable' is the definition.
(thesaurus)

'dim feller now surprisingly' is the wordplay.
'surprisingly' indicates an anagram.
'dim'+'feller'+'now'='dimfellernow'
'dimfellernow' with letters rearranged gives 'WELL-INFORMED'.

(Another definition for well-informed that I've seen is " Knowing the latest".)

I've seen this clue in The Times.

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