old ironsides has 1 distinct synonym spread across 1 of its 1 sense. 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.
a United States 44-gun frigate that was one of the first three naval ships built by the United States; it won brilliant victories over British frigates during the War of 1812 and is without doubt the most famous ship in the history of the United States Navy; it has been rebuilt and is anchored in the Charlestown Navy Yard in Boston
Synonyms, antonyms and the broader and narrower relations for old ironsides come from Princeton University’s WordNet. Full sources and licences.