heartless vs severe

heartless

adj
  • Without feeling, emotion, or concern for others; uncaring. 

  • Without a physical heart. 

severe

adj
  • Sober, plain in appearance, austere. 

  • Very bad or intense. 

  • Strict or harsh. 

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