pom-pom vs revolver

pom-pom

noun
  • A rapid-firing small-calibre cannon used especially as an anti-aircraft gun. 

revolver

noun
  • A handgun with a revolving chamber enabling several shots to be fired without reloading. 

  • Any (personal) firearm with such a mechanism. 

  • Synonym of revolving line of credit 

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