inform vs subtle

inform

adj
  • Without regular form; shapeless; ugly; deformed. 

verb
  • To give form or character to; to inspire (with a given quality); to affect, influence (with a pervading principle, idea etc.). 

  • To act as an informer; denounce. 

  • To communicate knowledge to. 

  • To impart information or knowledge. 

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