eponym vs first name

eponym

noun
  • A real or fictitious person's name that has given rise to the name of a particular item. 

  • A word formed from a real or fictive person’s name. 

  • A word formed from a real or fictive place or thing. 

first name

noun
  • The first element of a full name in cultures that place the given name first. 

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