key word vs nomen

key word

nomen

noun
  • The name of a citizen of Ancient Rome, designating them as a member of a gens. 

  • The birth name of a pharaoh, the fifth of the five names of the royal titulary, traditionally encircled by a cartouche and preceded by the title zꜣ-rꜥ. 

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