Sentence:  Hoag pushed open the <WSD>door</WSD> : at the far end of the long dark room Muller was faintly silhouetted against the window , the rifle still raised ; he stood with his feet apart on a kitchen table he had dragged to the sill . 
Meaning of the word marked with <WSD> tags:  a swinging or sliding barrier that will close the entrance to a room or building or vehicle