nonsharp vs subtle

nonsharp

adj
  • dulled or intentionally blunt. 

  • Pertaining to a certain type of distillation. 

subtle

adj
  • Barely noticeable, not obvious, indistinct. 

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

  • Cleverly contrived. 

  • Cunning, skillful. 

  • Insidious. 

  • Hard to grasp; not obvious or easily understood. 

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