"Wizard spread,” Bunter finally expressed (4)

I believe the answer is:

mage

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'wizard' is the definition.
(mage can mean a wizard or magician)

I cannot understand how the rest of the clue works.

(Other definitions for mage that I've seen before include "Wise man" , "Learned person (arch.)" , "Sorcerer" .)

I've seen this clue in The Independent.

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