To rumple, to make a mess of.

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1806.  

          And what can turn their rage? Kind condescension
To do observance, make obliging mention,
Wink lovingly, mux chastity away.
The Balance, Aug. 26, p. 272/2.    

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1877.  Stop muxin’ that bread!… you’ve eaten enough for twenty people. I shan’t have you muxing and gauming up your victuals.—J. M. Bailey, ‘They all Do It,’ p. 22 (Bartlett).

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