Sentence:  One Appalachian solution to the problem of adding needed living space to an existing small cabin was the <WSD>"dogtrot</WSD>", sometimes called the dogrun, possum trot, two pens-and-a-passage, double house, or erroneously the double pen. 
Meaning of the word marked with <WSD> tags:  (Southern US) A type of house with an open breezeway or hallway between two sections of a house.