cognomen vs surname

cognomen

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

  • A nickname or epithet by which someone is identified. 

  • Surname. 

surname

noun
  • The cognomen of Roman names. 

  • The name a person shares with other members of that person's family, distinguished from that person's given name or names; a family name. 

verb
  • To call by a surname. 

  • To give a surname to. 

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