Quack is the rather silly noise that a duck makes.[1]
Quack is also a term for a deceitful person who pretends to be an expert in some field, especially medicine but doesn't really know very much and makes preposterous claims. A quack may also be someone who knows a great deal and makes preposterous claims to deceive people.[2]
See also[]
- Pseudoscience
- Pseudoscience criteria
- Religious leader