john has 18 distinct synonyms spread across 5 of its 5 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.
youngest son of Henry II; King of England from 1199 to 1216; succeeded to the throne on the death of his brother Richard I; lost his French possessions; in 1215 John was compelled by the barons to sign the Magna Carta (1167-1216)
(New Testament) disciple of Jesus; traditionally said to be the author of the 4th Gospel and three epistles and the book of Revelation
the last of the four Gospels in the New Testament
Synonyms, antonyms and the broader and narrower relations for john come from Princeton University’s WordNet. Full sources and licences.