Gnostic vs subtle

Gnostic

adj
  • Of, or relating to, intellectual or spiritual knowledge 

  • Of, or relating to Gnosticism 

noun
  • A believer in Gnosticism 

subtle

adj
  • Hard to grasp; not obvious or easily understood. 

  • Tenuous; rarefied; of low density or thin consistency. 

  • Barely noticeable, not obvious, indistinct. 

  • Cleverly contrived. 

  • Cunning, skillful. 

  • Insidious. 

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