Wind dispersed a rare mist (9)
I believe the answer is:
airstream
'wind' is the definition.
(airstream is a kind of wind)
'dispersed a rare mist' is the wordplay.
'dispersed' is an anagram indicator.
'a'+'rare'+'mist'='araremist'
'araremist' anagrammed gives 'AIRSTREAM'.
(Other definitions for airstream that I've seen before include "wash" , "What might waft" , "Jet" , "blow" , "Atmospheric current" .)