door

out of doors | American Dictionary

out of doors
adverb[ not gradable ]
us/ˈoʊt əv ˈdɔrz/
outdoors:
They waited out of doors in the cold for tickets.
out-of-doors
adjective[ not gradable ]
us/ˈoʊt·əvˈdɔrz/
outdoor:
They have some out-of-doors activities planned.
out-of-doors
noun
 the out-of-doors
the outdoors:
I prefer being in the out-of-doors.