WordNet records no synonym and no antonym for pythian games. It is the only member of its synset, which is common for technical, taxonomic and single-sense vocabulary — there is no other English word that means the same thing. The broader and narrower terms below are the useful relations in that case.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
the ancient Panhellenic celebration at Delphi held every four years in the third year of the Olympiad in honor of Apollo
Synonyms, antonyms and the broader and narrower relations for pythian games come from Princeton University’s WordNet. Full sources and licences.