argonaut vs trekker

argonaut

noun
  • An adventurer on a dangerous but rewarding quest. 

  • Any of several species of shelled octopods of the family Argonautidae (of which only the genus Argonauta is not extinct). 

trekker

noun
  • One who treks; a hiker. 

  • A person who spent the night in a rural area, rather than his home, during bombing raids. 

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