lyons has 3 distinct synonyms spread across 3 of its 3 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. WordNet records no antonym for it — antonymy is a relation between word forms rather than concepts, so it is deliberately sparse.
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 council in 1274 that effected a temporary reunion of the Greek Orthodox with the Roman Catholic Church
Synonyms, antonyms and the broader and narrower relations for lyons come from Princeton University’s WordNet. Full sources and licences.
the council of the Western Church in 1245 that excommunicated Holy Roman Emperor Frederick II and planned a new crusade against the Holy Land