Definitions

1. noun

a person who pretends to be a doctor or other medical expert, often by advertising false medical treatments or products.

“The media exposed the quackster who was selling fake remedies online.”

2. noun

an unscrupulous person who exploits others, especially by pretending to have knowledge or skills they do not possess.

“The con artist was a notorious quackster who swindled people out of their life savings.”