Balloon blown, as spinning left (8)
I believe the answer is:
snowball
'balloon' is the definition.
(thesaurus)
'blown as spinning left' is the wordplay.
'spinning' indicates anagramming the letters.
'left' becomes 'l' (common abbreviation).
'blown'+'as'='blownas'
'blownas' with letters rearranged gives 'snowbal'.
'snowbal'+'l'='SNOWBALL'
(Other definitions for snowball that I've seen before include "Cocktail; grow rapidly" , "Missile thrown by children in hard winter" , "Cold sphere" , "Mushroom" , "Cocktail made from lemonade and advocaat" .)