Mine was transformed by a clever fellow (4,3)

I believe the answer is:

wise man

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'a clever fellow' is the definition.
The answer and definition can be both people as well as being singular nouns.
Maybe there's an association between them I don't understand?

'mine was transformed' is the wordplay.
'transformed' indicates anagramming the letters.
'mine'+'was'='minewas'
'minewas' is an anagram of 'WISE MAN'.

'by' is the link.

Can you help me to learn more?

(Other definitions for wise man that I've seen before include "Fellow with a gift" , "Experienced veteran" , "Sage" .)

I've seen this clue in the Evening Standard.

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