irritant vs wormwood

irritant

noun
  • A source of irritation. 

  • Any medication designed to cause irritation 

adj
  • Causing irritation or inflammation. 

  • Rendering null and void; conditionally invalidating. 

wormwood

noun
  • Something that causes bitterness or affliction; a cause of mortification or vexation. 

  • An intensely bitter herb (Artemisia absinthium and similar plants in genus Artemisia) used in medicine, in the production of absinthe and vermouth, and as a tonic. 

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