Sentence:  I was drunk with excitement and the smell of <WSD>gunpowder</WSD> that came floating down from the road , and the fact that I was not afraid now , but only waiting to know what to do next . 
Meaning of the word marked with <WSD> tags:  a mixture of potassium nitrate, charcoal, and sulfur in a 75:15:10 ratio which is used in gunnery, time fuses, and fireworks