1) A door within a dwelling-house, not opening to the outside, and possibly less robust.
1637 In doores, out doors ... glasse windoes, chambers, etc, Kirkby Malzeard
1743 8 inn doors, one out door, Saddleworth
1773 one out doar making for the cotge, 10s 6d
one in dor making for the cotge 7s 6d, Oakenshaw.