Aboriginal vs sachem

Aboriginal

noun
  • An Aboriginal inhabitant of Australia. 

name
  • Any of the native languages spoken by Australian aborigines. 

adj
  • Of or pertaining to Australian Aboriginal peoples, Aborigines, or their language. 

sachem

noun
  • A chief of one or several Native American tribe(s), especially of the Algonquians; a sagamore. 

  • A boss, a leader. 

  • A high-ranking officer of the Tammany Hall political organization. 

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