Tributary of Lune fit for swimming around noon (8)

I believe the answer is:

influent

'tributary' is the definition.
(influent can mean a tributary)

'lune fit for swimming around noon' is the wordplay.
'for swimming' indicates anagramming the letters (letters swim around).
'around' indicates putting letters inside.
'noon' becomes 'n'.
'lune'+'fit'='lunefit'
'lunefit' is an anagram of 'ifluent'.
'ifluent' placed around 'n' is 'INFLUENT'.

'of' is the link.

I've seen this clue in The Guardian.

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