override

(noun) a manually operated device to correct the operation of an automatic device.

(noun) the act of nullifying; making null and void; counteracting or overriding the effect or force of something. Synonyms: nullification.

(verb) rule against. Synonyms: overrule, overturn, overthrow, reverse. Example: "The republicans were overruled when the house voted on the bill."

(verb) prevail over. Example: "Health considerations override financial concerns."

(verb) counteract the normal operation of (an automatic gear shift in a vehicle).

(verb) ride (a horse) too hard.