How's that for charm? (6)

I believe the answer is:

appeal

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'that for charm?' is the definition.
('appeal' can be a synonym of 'charm')

I don't understand the rest of the clue.

(Other definitions for appeal that I've seen before include "Charity fund-drive" , "Allure, attraction" , "Charm in higher court?" , "Make heartfelt request" , "A crustacean" .)

I've seen this clue in The Sun.

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