decorticate vs shale

decorticate

verb
  • To peel or remove the bark, husk, or outer layer from something. 

  • To surgically remove the surface layer, membrane, or fibrous cover of an organ etc. 

adj
  • Having had the cortex removed 

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 decorticate and shale occurred in a corpus of books? (source: Google Ngram Viewer )