malignity vs rivalry

malignity

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

  • A non-benign cancer; a malignancy. 

rivalry

noun
  • The characteristic of being a rivalrous good, such that it can be consumed or used by only one person at a time. 

  • An ongoing relationship between (usually two) rivals who compete for superiority. 

  • Any competition between two or more things or factors. 

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