Tornado (7)
'tornado' is the definition.
(I know that tornado can be written as twister)
This is the entire clue.
(Other definitions for twister that I've seen before include "One-eyed menace" , "Tornado (American)" , "Tornado (colloq.)" , "Colloquial name for a tornado" , "Funnel-shaped wind" .)
(Other definitions for wiser that I've seen before include "More judicious" , "showing more understanding?" , "More sensible" , "More knowing" , "Comparatively intelligent" .)