Quackery is a derogatory term used to describe unscientific medical practices. Random House Dictionary describes a "quack" as a "fraudulent or ignorant pretender to medical skill" or "a person who pretends, professionally or publicly, to have skill, knowledge, or qualifications he or she does not possess; a charlatan."
The word "quack" derives from the archaic word "quacksalver," of Dutch origin (spelled kwakzalver in contemporary Dutch), meaning "boaster who applies a salve." The meaning of the German word "Quacksalber" is "questionable salesperson (literal translation: quack salver)." In the Middle Ages the word quack meant "shouting". The quacksalvers sold their wares on the market shouting in a loud voice.
"Health fraud" is often used as a synonym for quackery, but this use can be problematic, since quackery can exist without fraud, a word which implies deliberate deception.
