Bananas for sale getting cold in open air (8)
I believe the answer is:
alfresco
'open air' is the definition.
(thesaurus)
'bananas for sale getting cold' is the wordplay.
'bananas' indicates an anagram (informal term for mad).
'getting' says to put letters next to each other.
'cold' becomes 'c' (eg on taps).
'for'+'sale'='forsale'
'forsale' put after 'c' is 'cforsale'.
'cforsale' anagrammed gives 'ALFRESCO'.
'in' acts as a link.
(Other definitions for alfresco that I've seen before include "In the open air" , "Located outdoors" , "where it's cool" , "exposed to the fresh air" , "out of the house" .)