decapitate vs shale

decapitate

verb
  • To remove the head of. 

  • To oust or destroy the leadership or ruling body of (a government etc.). 

shale

verb
  • To take off the shell or coat of. 

noun
  • A shell or husk; a cod or pod. 

  • A fine-grained sedimentary rock of a thin, laminated, and often friable, structure. 

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