imperatorial vs prominent

imperatorial

adj
  • Commanding; authoritative. 

  • Relating to the title or office of imperator. 

prominent

adj
  • eminent; distinguished above others 

  • standing out, or projecting; jutting; protuberant 

  • likely to attract attention from its size or position; conspicuous 

noun
  • Any of various moths having a conspicuous projection on the inner margin of the wings. 

  • In Nazi concentration camps, an inmate entrusted with minor supervisory duties and rewarded with perquisites. 

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