agon vs Pythian Games

agon and Pythian Games both are nouns.

Word	Noun	Adjective	Verb	Adverb
agon	Yes	No	No	No
Pythian Games	Yes	No	No	No

As nouns, Pythian Games is a hyponym of agon; that is, Pythian Games is a word with a more specific, narrower meaning than agon:

agon: a festivity in ancient Greece at which competitors contended for prizes
Pythian Games: the ancient Panhellenic celebration at Delphi held every four years in the third year of the Olympiad in honor of Apollo

Other hyponyms of agon include Isthmian Games, Nemean Games, Olympian Games, Olympic Games.

agon (noun)	Pythian Games (noun)
a festivity in ancient Greece at which competitors contended for prizes	the ancient Panhellenic celebration at Delphi held every four years in the third year of the Olympiad in honor of Apollo