• In one sense, it meant a contest, competition, especially the Olympic Games , or challenge that was held in connection with religious festival
  Religious festival
  A religious festival is a time of special importance marked by adherents to that religion. Religious festivals are commonly celebrated on recurring cycles in a calendar year or lunar calendar...
  
  s.
• In its broader sense of a struggle or contest, agon referred to a contest in athletics, chariot or horse racing, music or literature at a public festival in ancient Greece.
• Agon was also a mythological
  Greek mythology
  Greek mythology is the body of myths and legends belonging to the ancient Greeks, concerning their gods and heroes, the nature of the world, and the origins and significance of their own cult and ritual practices. They were a part of religion in ancient Greece...
  
   personification of the contests listed above. This god was represented in a statue at Olympia
  Olympia, Greece
  Olympia , a sanctuary of ancient Greece in Elis, is known for having been the site of the Olympic Games in classical times, comparable in importance to the Pythian Games held in Delphi. Both games were held every Olympiad , the Olympic Games dating back possibly further than 776 BC...
  
   with halteres
  Halteres (ancient Greece)
  Halteres were a type of dumbbells used in Ancient Greece. In ancient Greek sports, halteres were used as lifting weights, and also as weights in their version of the long jump, which was probably a set of three jumps. Halteres were held in both hands to allow an athlete to jump a greater distance;...
  
  (dumbbells) in his hands. This statue was a work of Dionysius
  Dionysius
  The Graeco-Roman name Dionysius, deriving from the name of the Thracian god Dionysus, was exceedingly common, and many ancient people, famous and otherwise, bore it. It remains a common name today in the form Dennis . The modern Greek form of the name is Dionysios or Dionysis. The Spanish form of...
  
  , and dedicated by a Smicythus of Rhegium.
• In Ancient Greek drama, particularly old comedy (fifth century B.C.), agon refers to the formal convention according to which the struggle between the characters
  Fictional character
  A character is the representation of a person in a narrative work of art . Derived from the ancient Greek word kharaktêr , the earliest use in English, in this sense, dates from the Restoration, although it became widely used after its appearance in Tom Jones in 1749. From this, the sense of...
  
   should be scripted in order to supply the basis of the action. Agon is a formal debate which takes place between the chief characters in a Greek play, protagonist and antagonist, usually with the chorus
  Greek chorus
  A Greek chorus is a homogenous, non-individualised group of performers in the plays of classical Greece, who comment with a collective voice on the dramatic action....
  
   acting as judge. The meaning of the term has escaped the circumscriptions of its classical origins to signify, more generally, the conflict on which a literary work turns.
• Harold Bloom
  Harold Bloom
  Harold Bloom is an American writer and literary critic, and is Sterling Professor of Humanities at Yale University. He is known for his defense of 19th-century Romantic poets, his unique and controversial theories of poetic influence, and his prodigious literary output, particularly for a literary...
  
   in The Western Canon uses the term agon to refer to the attempt by a writer to resolve an intellectual conflict between his ideas and the ideas of an influential predecessor in which "the larger swallows the smaller", such as in chapter 18, Joyce
  James Joyce
  James Augustine Aloysius Joyce was an Irish novelist and poet, considered to be one of the most influential writers in the modernist avant-garde of the early 20th century...
  
  's Agon with Shakespeare
  William Shakespeare
  William Shakespeare was an English poet and playwright, widely regarded as the greatest writer in the English language and the world's pre-eminent dramatist. He is often called England's national poet and the "Bard of Avon"...
  
  .

Other sources

• Joel Trapido (1949) The Language of the Theatre: I. The Greeks and Romans Educational Theatre Journal, Vol. 1, No. 1 (Oct., 1949), pp. 18–26 doi:10.2307/3204106