override in WordNet English dictionary

1. the act of nullifying; making null and void; counteracting or overriding the effect or force of something
   nullification  override 
   
2. a manually operated device to correct the operation of an automatic device
   override 
   

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