argonaut vs roamer

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). 

roamer

noun
  • One who roams. 

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