Cheers that cut short negative knocking, spiteful initially (6)

I believe the answer is:

thanks

'cheers' is the definition.
('cheers' can informally mean 'thank you')

'that cut short negative knocking spiteful initially' is the wordplay.
'cut short' means to remove the last letter.
'initially' says to take the initial letters.
The first letters of 'negative knocking spiteful' is 'nks'.
'that' with its last letter taken away is 'tha'.
'tha'+'nks'='THANKS'

(Other definitions for thanks that I've seen before include "Brief conventional expression of gratitude" , "Word of appreciation" , "Ta" , "Expressions of gratitude" , "Word of gratitude" .)

I've seen this clue in The Times.

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