Wind vortex (7)
I believe the answer is:
tornado
'wind vortex' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for tornado that I've seen before include "A violent and destructive whirlwind" , "Cyclone, twister" , "Violent whirlwind over land" , "Terrible storm" , "Severe wind" .)