quash

Verb

• declare invalid
  • The contract was annulled
    
  • void a plea
    

• put down by force or intimidation
  • The government quashes any attempt of an uprising
    
  • China keeps down her dissidents very efficiently
    
  • The rich landowners subjugated the peasants working the land
    

Related words

• Synonyms: 
  invalidate , annul , void , avoid , nullify , repress , keep down , subdue , subjugate , reduce
• Antonyms: 
  validate , formalize , formalise