Quackery is the promotion of fraudulent or ignorant medical practices. A quack is 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 term quack is a clipped form of the archaic term , from a "hawker of salve". In the Middle Ages the term quack meant "shouting". The quacksalvers sold their wares on the market shouting in a loud voice.

Quackery is the promotion of fraudulent or ignorant medical practices. A quack is 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 term quack is a clipped form of the archaic term , from a "hawker of salve". In the Middle Ages the term quack meant "shouting". The quacksalvers sold their wares on the market shouting in a loud voice.