Definition of quack
- quack Noun The sound made by a duck.
- quack Verb To make a noise like a duck.
- quack Noun A fraudulent healer or incompetent doctor of medicine, an impostor who claims to have qualifications to practice medicine.
- quack Noun A charlatan. "
- quack Noun A doctor.
- quack Verb To practice, commit quackery.
- quack Adjective falsely presented as having medicinal powers.