WordNet records no synonym and no antonym for epideictic oratory. 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.
a type of oratory used to eulogize or condemn a person or group of people
“Pericles' funeral oration for Athenians killed in the Peloponnesian War is a famous example of epideictic oratory”
Synonyms, antonyms and the broader and narrower relations for epideictic oratory come from Princeton University’s WordNet. Full sources and licences.