Why are bad doctors called quacks?

The term "quack" has been used to refer to unqualified or fraudulent doctors since the 16th century. It was originally a term of abuse levelled at charlatans and unlicensed medical practitioners, but has since been used to refer to any doctor who is perceived to be incompetent, untrustworthy, or unethical.

There are a few possible explanations for why bad doctors are called quacks. One is that the term is onomatopoeic, meaning that it imitates the sound of a duck quacking. This may have been used as a way to dismiss or mock doctors who were perceived to be talking nonsense or making false claims.

Another possibility is that the term "quack" is derived from the Dutch word "kwakzalver", which means "boaster" or "braggart". This term was originally used to refer to travelling salesmen who sold fake or ineffective medicines, and it may have been applied to bad doctors by association.

Whatever the origin, the term "quack" is now widely used to refer to bad doctors. It is a term of contempt and ridicule, and it is a warning to patients to be wary of those who claim to be medical professionals but do not have the necessary training or qualifications.