open air

open air
    n 1: where the air is unconfined; "he wanted to get outdoors a
         little"; "the concert was held in the open air"; "camping
         in the open" [syn: {outdoors}, {out-of-doors}, {open air},
         {open}]
    

22 Moby Thesaurus words for "open air":
      aerial, aeriform, aery, airish, airlike, airy, alfresco,
      atmospheric, breezy, ethereal, exposed, light, open, out,
      out-of-door, out-of-doors, outdoor, outside, pneumatic, roomy,
      tropospheric, without