Tornado; cheat (7)
I believe the answer is:
twister
This clue is a double definition.
'tornado' is the first definition.
(I know that tornado can be written as twister)
'cheat' is the second definition.
(I've seen this before)
(Other definitions for twister that I've seen before include "Con artist - tornado" , "Crook - tornado" , "Funnel-shaped wind" , "Dishonest person" , "Tornado (American)" .)