[Origin unascertained.] A door flush with the wall in which it stands, and usually painted or papered so as to be indistinguishable from it.
1800. Mrs. Hervey, Mourtray Fam., II. 159. Emma … darted out through a gib-door, covered with pictures, which had struck her eye while he was speaking.
1820–2. Pyne, Wine & Walnuts (1824), II. ix. 132. The delighted bookseller opened a jib door … that went from the side of the shop to a steep narrow staircase.
1852. Lomax & Gunyon, Encycl. Archit., s.v., The use of a jib-door is to preserve the symmetry of an apartment, where only one door is wanted, nearer to one end of the partition than the other.
