Additional ring inside pollen producer (7)

I believe the answer is:

another

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'additional' is the definition.
(thesaurus)

'ring inside pollen producer' is the wordplay.
'ring' becomes 'gang' (synonyms).
'inside' says to take the centre.
'pollen producer' becomes 'other' (I can't justify this - if you can you should believe this answer much more).
The middle letters of 'gang' are 'an'.
'an'+'other'='ANOTHER'

Can you help me to learn more?

(Other definitions for another that I've seen before include "On earth (anag.)" , "encore?" , "A different one" , "Additional, one more" , "Somebody else" .)

I've seen this clue in the Sydney Morning Herald.

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