cognomen vs nameword

cognomen

noun
  • A nickname or epithet by which someone is identified. 

  • The third part of the name of a citizen of Ancient Rome. 

  • Surname. 

nameword

noun
  • A designation or name given to an object, person or location. 

  • A noun. 

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