eponym vs identifier

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. 

identifier

noun
  • Someone who identifies; a person who establishes the identity of someone or something. 

  • One who identifies as a particular type or role; one who says and believes that they are a certain thing. 

  • A formal name used in source code to refer to a variable, function, procedure, package, etc. or in an operating system to refer to a process, user, group, etc. 

  • A primary key. 

  • A guidebook that helps determine the specific class of an object (such as a mushroom, herb, fish, bird, drug, or mineral), or its individual identity (such as that of a star). 

  • Something that identifies or uniquely points to something or someone else. 

  • A code that distinguishes a particular element from all other elements in a document. 

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