park has 9 distinct synonyms spread across 5 of its 8 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 large area of land preserved in its natural state as public property
“there are laws that protect the wildlife in this park”
a piece of open land for recreational use in an urban area
“they went for a walk in the park”
a lot where cars are parked
a gear position that acts as a parking brake
“the put the car in park and got out”
Synonyms, antonyms and the broader and narrower relations for park come from Princeton University’s WordNet. Full sources and licences.