WordNet records no synonym and no antonym for new netherland. It is the only member of its synset, 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 Dutch colony in North America along the Hudson and lower Delaware rivers although the colony centered in New Amsterdam; annexed by the English in 1664
Synonyms, antonyms and the broader and narrower relations for new netherland come from Princeton University’s WordNet. Full sources and licences.