Definition as I understand it is:
Strictest,
1- One who prescribes quacksilber as medicince. Quacksilber (sp?) is a Swedish word meaning mercury, a well-known
poison.
A bit looser,
2- One who prescribes poison(s) as medicine. Practically all drugs prescribed by M.D.s, others.
Broadest,
3- One who gives bad health advice.
Hope we can all talk about the same thing. (Maybe dreaming :) )
William