On the phone called man for a ‘Macbeth’ prop (8)

I believe the answer is:

cauldron

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But I can't explain it at all! Could you help me understand?

(Other definitions for cauldron that I've seen before include "A large deep pot for boiling things" , "Witches' pot" , "Witches' vessel" , "Very large metal pot for boiling" , "Large cooking pot" .)

I've seen this clue in The Hindu.

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