area has 9 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 particular geographical region of indefinite boundary (usually serving some special purpose or distinguished by its people or culture or geography)
“it was a mountainous area”
a part of an animal that has a special function or is supplied by a given artery or nerve
“in the abdominal region”
a part of a structure having some specific characteristic or function
“the spacious cooking area provided plenty of room for servants”
Synonyms, antonyms and the broader and narrower relations for area come from Princeton University’s WordNet. Full sources and licences.