WordNet records no synonym and no antonym for vaisya. 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 mercantile and professional Hindu caste; the third of the four main castes
the third of the four varnas: the commoners or yeoman farmers or mercantile and professional category
Synonyms, antonyms and the broader and narrower relations for vaisya come from Princeton University’s WordNet. Full sources and licences.