coterie vs severance

coterie

noun
  • A communal burrow of prairie dogs. 

  • A circle of people who associate with one another for a common purpose. 

severance

noun
  • A separation. 

  • The act of severing or the state of being severed. 

  • A severance payment. 

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