Auditor’s humble appearance (4)

I believe the answer is:

mien

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'appearance' is the definition.
(I've seen this before)

I can't explain the remainder of the clue.

(Other definitions for mien that I've seen before include "attitude" , "A countenance like mine" , "Dignified manner" , "A manner like mine" , "A face - maybe mine" .)

I've seen this clue in The Times.

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