Mistake, whichever way one looks at it (4)

I believe the answer is:

boob

This clue is a double definition.

'mistake' is the first definition.
(thesaurus)

'whichever way one looks at it' is the second definition.

(Other definitions for boob that I've seen before include "Mistake; breast (sl.)" , "Error" , "Embarrassing mistake" , "Slip" , "Blunder (colloq.)" .)

I've seen this clue in The Telegraph.

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