quack
     adj : medically unqualified; "a quack doctor" [syn: {quack(a)}]
     n 1: an untrained person who pretends to be a physician and who
          dispenses medical advice
     2: the harsh sound of a duck
     v 1: utter quacking noises; "The ducks quacked"
     2: act as a medical quack or a charlatan
Source: WordNet® 2.0