impenetrable vs plotty

impenetrable

adj
  • Incomprehensible; fathomless; inscrutable. 

  • Opaque; obscure; not translucent or transparent. 

  • Not penetrable. 

noun
  • A person not openly given to friendship. 

plotty

adj
  • Having a complicated plot. 

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