WordNet records no synonym and no antonym for wagnerian. It is the only member of each of its synsets, 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 follower of the theories or an admirer of the music of Richard Wagner
1 of the 2 recorded senses carries no synonym, antonym or related term, so it is not shown above. Every sense, with its definition and examples, is on the full entry for wagnerian.
Synonyms, antonyms and the broader and narrower relations for wagnerian come from Princeton University’s WordNet. Full sources and licences.