buffalo has 4 distinct synonyms spread across 2 of its 5 senses. 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.
large shaggy-haired brown bison of North American plains
a city on Lake Erie in western New York (near Niagara Falls)
Synonyms, antonyms and the broader and narrower relations for buffalo come from Princeton University’s WordNet. Full sources and licences.
any of several Old World animals resembling oxen including, e.g., water buffalo; Cape buffalo