WordNet records no synonym and no antonym for handball. 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 small rubber ball used in playing the game of handball
a game played in a walled court or against a single wall by two or four players who strike a rubber ball with their hands
Synonyms, antonyms and the broader and narrower relations for handball come from Princeton University’s WordNet. Full sources and licences.