Viking vs freebooter

Viking

noun
  • A player on the Minnesota Vikings NFL team. 

  • A stock character common in the fantasy genre, namely a barbarian, generally equipped with an axe or sword and a helmet adorned with horns. 

  • A Norseman (medieval Scandinavian). 

  • An ethnic Swede, Norwegian, Dane, Icelander or Faroe Islander. 

  • Scandinavian/Northern European seafarers, most familiarly raiders and pirates during the Viking age. 

name
  • A sea area between Scotland and Norway 

  • A city in Minnesota 

  • A town in Alberta, Canada 

freebooter

noun
  • One who rehosts online media without authorization; one who freeboots. 

  • An adventurer who pillages, plunders or wages ad-hoc war on other nations. 

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