Incorrectly name new long distance around the very thick slice (8)

I believe the answer is:

mislabel

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'new long distance around the very thick slice' is the definition.
I can't tell whether this defines the answer.

'incorrectly name' is the wordplay.
'incorrectly' becomes 'mis' (I am not sure about this - if you are sure you should believe this answer much more).
'name' becomes 'label'.
'mis'+'label'='MISLABEL'

Can you help me to learn more?

(Another definition for mislabel that I've seen is " Classify incorrectly".)

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

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