From The Collaborative International Dictionary of English v.0.48 :
Outdoors \Out"doors`\, adv. Out of the house; out of doors; in the open air; abroad. [1913 Webster +PJC]From WordNet (r) 3.0 (2006) :
outdoors adv 1: outside a building; "in summer we play outside" [syn: outside, outdoors, out of doors, alfresco] [ant: indoors, inside] 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]