From WordNet (r) 3.0 (2006) [wn]:
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"
From The Collaborative International Dictionary of English v.0.48 [gcide]:
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.
[1913 Webster]