refresher vs stimulant

refresher

noun
  • Something that refreshes. 

  • An equity grant given by a company to an existing employee, as opposed to an initial grant given to new employees. 

  • A review to refresh or renew knowledge. 

  • A fee paid to counsel to continue with a case, especially one that was adjourned. 

stimulant

noun
  • Something that promotes activity, interest, or enthusiasm. 

  • A substance that acts to increase physiological or nervous activity in the body. 

adj
  • Acting as a stimulant. 

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