Butcher Butcher with alien siege engine of old (9)

I believe the answer is:

trebuchet

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'siege engine of old' is the definition.
I can't tell whether this defines the answer.

'butcher butcher with alien' is the wordplay.
'butcher' indicates an anagram.
'with' means one lot of letters go next to another.
'alien' becomes 'et' (extra terrestrial).
'butcher' with letters rearranged gives 'trebuch'.
'trebuch'+'et'='TREBUCHET'

Can you help me to learn more?

(Other definitions for trebuchet that I've seen before include "Medieval siege engine" , "Old weapon" , "Old slinger" , "Medieval engine of war" , "onager?" .)

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

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