Sentence:  Men blew <WSD>dust</WSD> on objects in a room on the seventeenth floor of the Hotel Dumont and blew it off again , and did the same in a tiny , almost airless room in a tenement in the West Forties . 
Meaning of the word marked with <WSD> tags:  fine powdery material such as dry earth or pollen that can be blown about in the air