Dubious character of tornado (7)

I believe the answer is:

twister

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'tornado' is the definition.
(I know that tornado can be written as twister)

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for twister that I've seen before include "See 12" , "'sixties dancer?" , "Crook - tornado" , "A swindler or a cyclone" , "Colloquial name for a tornado" .)

I've seen this clue in The Sun.

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