Promoter of Mac & iPhone forgot euro conversion (8)

I believe the answer is:

champion

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'promoter' is the definition.
(thesaurus)

I don't understand how the rest of the clue works.

(Other definitions for champion that I've seen before include "Champ" , "Splendid" , "Stand up for" , "Competitor who has defeated all others" , "gain position on top" .)

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

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