Not quite sober, show dissent (5)

I believe the answer is:

demur

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

I cannot understand how the remainder of the clue works.

(Other definitions for demur that I've seen before include "Protest or disagree mildly" , "Waver" , "Protest mildly, show reluctance" , "Hesitation" , "Raise scruples" .)

I've seen this clue in The Guardian.

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