Cheating behaviour surprising to umpires (9)

I believe the answer is:

imposture

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'cheating behaviour' is the definition.
'imposture' can be an answer for 'cheating' (thesaurus). I'm unsure of the 'behaviour' bit.

'surprising to umpires' is the wordplay.
'surprising' is an anagram indicator.
'to'+'umpires'='toumpires'
'toumpires' is an anagram of 'IMPOSTURE'.

Can you help me to learn more?

(Other definitions for imposture that I've seen before include "deception" , "Trick" , "Pretending to be another person" , "Assumption of a false identity" , "Fraud" .)

I've seen this clue in The Independent.

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