WordNet records no synonym and no antonym for whig. It is the only member of each of its synsets, 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 member of the political party that urged social reform in 18th and 19th century England; was the opposition party to the Tories
a supporter of the American Revolution
a member of the Whig Party that existed in the United States before the American Civil War
Synonyms, antonyms and the broader and narrower relations for whig come from Princeton University’s WordNet. Full sources and licences.