In the open air, exterior (7)
I believe the answer is:
outside
I believe this is a double definition.
'in the open air' is the first definition.
(I've seen this in another clue)
'exterior' is the second definition.
(synonyms)
(Other definitions for outside that I've seen before include "Where smokers now often must go" , "having emerged from the tunnel?" , "Without" , "Not indoors" , "External surface" .)