convenience vs irritation

convenience

noun
  • Any object that makes life more convenient; a helpful item. 

  • The quality of being convenient. 

  • A convenient time. 

verb
  • To make convenient 

irritation

noun
  • A things or person that annoys 

  • A condition of morbid excitability or oversensitiveness of an organ or part of the body; a state in which the application of ordinary stimuli produces pain or excessive or vitiated action. 

  • The state of being irritated 

  • The act of irritating or annoying 

  • a state of inflammation or painful reaction to allergy or cell-lining damage. 

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