Withoutdoors is an archaic compound of without ('outside of') + doors, paralleling outdoors, from Old English wiþūtan ('outside') and duru ('door'). In current use it is an adverb meaning "out of doors; outside (archaic)". That sense is explained by the older material without requiring a speculative semantic step: the inherited or borrowed base supplies the field of meaning, while the English formation fixes its modern role. The surface form is compositional: its joined elements remain visible in the modern word. The historical chain includes Old English wiþūtan and Old English duru. Related English forms include without, outdoors, and door. As a result, the modern word is best read as a negative, privative, or reversative formation built on a historically older base.