Noun

• S: (n) override (a manually operated device to correct the operation of an automatic device)
• S: (n) nullification, override (the act of nullifying; making null and void; counteracting or overriding the effect or force of something)

Verb

• S: (v) overrule, overturn, override, overthrow, reverse (rule against) "The Republicans were overruled when the House voted on the bill"
• S: (v) override (prevail over) "health considerations override financial concerns"
• S: (v) override (counteract the normal operation of (an automatic gear shift in a vehicle))
• S: (v) override (ride (a horse) too hard)