bitterness vs heat of passion

bitterness

noun
  • The quality of eliciting a bitter, humiliating or harsh feeling. 

  • The quality of having a bitter taste. 

  • Harsh cold. 

  • The quality of feeling bitter; acrimony, resentment; the quality of exhibiting such feelings. 

heat of passion

noun
  • An outburst of anger that leads one to commit a criminal act, and is itself influenced by preceding events that might cause a reasonable person to lose self control. 

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