Renowned fellow - a mostly quiet sort (6)

I believe the answer is:

famous

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'renowned' is the definition.
(synonyms)

'fellow a mostly quiet sort' is the wordplay.
'fellow' becomes 'F' (abbreviation - of a society etc.).
'mostly quiet sort' becomes 'mous' (I can't justify this - if you can you should believe this answer much more).
'f'+'a'+'mous'='FAMOUS'

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(Other definitions for famous that I've seen before include "Renowned, noted" , "Eminent" , "Renowned, celebrated" , "Well known" , "Well-known" .)

I've seen this clue in The Independent.

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