Sentence:  "Either a <WSD>skinny</WSD> had judged (correctly) that it was worth one of their buildings to try for one of us, or one of my own mates was getting mighty careless with fireworks" .."A congregation in church — a <WSD>skinny</WSD> flophouse — maybe even their defense headquarters. All I knew was that it was a very big room filled with more <WSD>skinnies</WSD> than I wanted to see in my whole life." 
Meaning of the word marked with <WSD> tags:  A skinny being.