Swirling storm (7)
I believe the answer is:
cyclone
'swirling storm' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for cyclone that I've seen before include "Whirlwind or twister" , "storm in the West Indies, say" , "Hurricane" , "Violent whirling wind" , "kind of weather?" .)