override has 5 distinct synonyms spread across 2 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.
prevail over
“health considerations override financial concerns”
Synonyms, antonyms and the broader and narrower relations for override come from Princeton University’s WordNet. Full sources and licences.
counteract the normal operation of (an automatic gear shift in a vehicle)
a manually operated device to correct the operation of an automatic device
the act of nullifying; making null and void; counteracting or overriding the effect or force of something