zone has 4 distinct synonyms spread across 4 of its 6 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.
a locally circumscribed place characterized by some distinctive features
any of the regions of the surface of the Earth loosely divided according to latitude or longitude
Synonyms, antonyms and the broader and narrower relations for zone come from Princeton University’s WordNet. Full sources and licences.
an area or region distinguished from adjacent parts by a distinctive feature or characteristic
(anatomy) any encircling or beltlike structure
separate or apportion into sections
“partition a room off”