Sentence:  In the old days, when there was a corrugated iron <WSD>thunderbox</WSD>, the Holts′ guests were told to approach it with caution: where other <WSD>thunderboxes</WSD> had redback spiders, the local ones tended to have taipans. 
Meaning of the word marked with <WSD> tags:  An outhouse or latrine: a rudimentary outdoor toilet.