diplomatic vs subtle

diplomatic

adj
  • Relating to diplomatics, or the study of old texts; paleographic. 

  • Exhibiting diplomacy; exercising tact or courtesy; using discussion to avoid hard feelings, fights or arguments. 

  • describing a publication of a text which follows a single basic manuscript, but with variants in other manuscripts noted in the critical apparatus 

  • Concerning the relationships between the governments of countries. 

noun
  • The science of diplomas, or the art of deciphering ancient writings and determining their age, authenticity, etc.; paleography. 

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 diplomatic and subtle occurred in a corpus of books? (source: Google Ngram Viewer )