leech vs quack

leech

noun
  • A healer. 

  • A person who derives profit from others in a parasitic fashion. 

  • The aft edge of a triangular sail. 

  • An aquatic blood-sucking annelid of class Hirudinea, especially Hirudo medicinalis. 

  • The vertical edge of a square sail. 

verb
  • To drain (resources) without giving back. 

  • To apply a leech medicinally, so that it sucks blood from the patient. 

quack

noun
  • Any doctor. 

  • A fraudulent healer, especially a bombastic peddler in worthless treatments, a doctor who makes false diagnoses for monetary benefit, or an untrained or poorly trained doctor who uses fraudulent credentials to attract patients 

  • Any similar charlatan or incompetent professional. 

  • The sound made by a duck. 

adj
  • Falsely presented as having medicinal powers. 

verb
  • To make a noise like a duck. 

  • Of a queen bee: to make a high-pitched sound during certain stages of development. 

  • To practice or commit quackery (fraudulent medicine). 

How often have the words leech and quack occurred in a corpus of books? (source: Google Ngram Viewer )