agon vs contention

agon

noun
  • A struggle or contest; conflict; especially between the protagonist and antagonist in a literary work. 

  • A contest in ancient Greece, as in athletics or music, in which prizes were awarded. 

  • A two-player board game played on a hexagonally-tiled board, popular in Victorian times. 

  • An intellectual conflict or apparent competition of ideas. 

contention

noun
  • Argument, contest, debate, strife, struggle. 

  • Competition by parts of a system or its users for a limited resource. 

  • A point maintained in an argument, or a line of argument taken in its support; the subject matter of discussion of strife; a position taken or contended for. 

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