nelson has 4 distinct synonyms spread across 1 of its 2 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.
English admiral who defeated the French fleets of Napoleon but was mortally wounded at Trafalgar (1758-1805)
any of several wrestling holds in which an arm is passed under the opponent's arm from behind and the hand exerts pressure on the back of the neck
Synonyms, antonyms and the broader and narrower relations for nelson come from Princeton University’s WordNet. Full sources and licences.