Sentence:  And there was the case of Tom Hepker , a machinist , who was referred by a friend to a health machine <WSD>quack</WSD> who treated him with a so-called diagnostic machine for what Doctor Fraud said was a system full of arsenic and strychnine . 
Meaning of the word marked with <WSD> tags:  an untrained person who pretends to be a physician and who dispenses medical advice