Spell whirl (4)
I believe the answer is:
turn
I believe this clue is a double definition.
'spell' is the first definition.
('turn' can be a synonym of 'spell')
'whirl' is the second definition.
(thesaurus)
(Other definitions for turn that I've seen before include "Go; reverse" , "Rotate for a performer's act" , "Shock - move - change course" , "Change direction" , "fit" .)