bitterness vs malignity

bitterness

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

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

  • The quality of having a bitter taste. 

  • Harsh cold. 

malignity

noun
  • The quality of being malign or malignant; badness, evilness, monstrosity, depravity, maliciousness. 

  • A non-benign cancer; a malignancy. 

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