assegai vs razor blade

assegai

noun
  • A slim hardwood spear or javelin with an iron tip, especially those used by Bantu peoples of Southern Africa. 

  • The tree species Curtisia dentata, the wood of which is traditionally used to make assegais. 

verb
  • To spear with an assegai. 

razor blade

noun
  • A thin piece of steel with a sharp edge that can be fitted into a razor. 

  • A replaceable cartridge in which razor blades are set, fitted into a razor. 

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