Sentence:  The visitor, observing that she held the door on the inside, and that, when the uncle tried to open it, there was a sharp adjuration of 'Don't, stupid!' and an appearance of loose stocking and flannel, concluded that the young lady was in an <WSD>undress</WSD>. 
Meaning of the word marked with <WSD> tags:  The state of having few or no clothes on.