reassurance vs stimulus

reassurance

noun
  • The act of confirming someone's opinion or impression. 

  • Reinsurance. 

  • The feeling of being reassured, of having confidence restored, of having apprehensions dispelled. 

stimulus

noun
  • An external phenomenon that has an influence on a system, by triggering or modifying an internal phenomenon; for example, a spur or incentive that drives a person to take action or change behaviour. 

  • A sting on the body of a plant or insect. 

  • Something external that elicits or influences a physiological or psychological activity or response, or that affects any of the sensory apparatuses. 

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