forbidden fruit vs pampelmoes

forbidden fruit

noun
  • A small variety of shaddock (Citrus maxima), or sometimes other citrus fruits. 

  • Illicit pleasure. 

  • The fruit forbidden to Adam. 

  • Something desired that cannot be had. 

pampelmoes

noun
  • Synonym of pomelo, as both a large fruit of Southeast Asia and as a catchall term for other related fruit such as the grapefruit. 

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