herb vs parasiticide

herb

noun
  • A plant whose roots, leaves or seeds, etc. are used in medicine. 

  • Cannabis. 

  • A lame or uncool person. 

  • Any green, leafy plant, or parts thereof, used to flavour or season food. 

  • A plant whose stem is not woody and does not persist beyond each growing season 

parasiticide

noun
  • Any substance used to kill parasites. 

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