eponym vs nom de Web

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. 

nom de Web

noun
  • A pseudonym used when publishing on the World Wide Web. 

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