Source : Webster's Revised Unabridged Dictionary (1913)

Outdoor \Out"door`\, a. [For out of door.]
   Being, or done, in the open air; being or done outside of
   certain buildings, as poorhouses, hospitals, etc.; as,
   outdoor exercise; outdoor relief; outdoor patients.

Source : WordNet®

outdoor
     adj 1: located, suited for, or taking place in the open air;
            "outdoor clothes"; "badminton and other outdoor
            games"; "a beautiful outdoor setting for the wedding"
            [syn: {outdoor(a)}, {out-of-door}, {outside}] [ant: {indoor(a)}]
     2: pertaining to or concerning the outdoors or outdoor
        activities; "outdoor education is the area of teacher
        training concerned with training for outdoor activities"