Much-changed friend (4)

I believe the answer is:

chum

'friend' is the definition.
(I know that chum is a type of friend)

'much-changed' is the wordplay.
'changed' indicates anagramming the letters.
'much' is an anagram of 'CHUM'.

(Other definitions for chum that I've seen before include "Salmon" , "Close friend (colloq.)" , "Pal, mate" , "Pal, buddy" , "Informally, a close friend" .)

I've seen this clue in The Daily Express.

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