grease gun vs pom-pom

grease gun

noun
  • A small machine gun, particularly the .45 calibre M3 used by the US in WW2. 

  • A levered device for forcing grease into machinery. 

pom-pom

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

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