playing field has 3 distinct synonyms spread across 1 of its 2 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.
the circumstances under which competition occurs
“the government's objective is to insure a genuinely level playing field for American industry and commerce in Europe”
a piece of land prepared for playing a game
“the home crowd cheered when Princeton took the field”
Synonyms, antonyms and the broader and narrower relations for playing field come from Princeton University’s WordNet. Full sources and licences.