invalidate

Verb

• take away the legal force of or render ineffective
  • invalidate a contract
    

• show to be invalid

• make invalid for use
  • cancel cheques or tickets
    

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

Related words

• Synonyms: 
  void , vitiate , nullify , cancel , annul , quash , avoid
• Antonyms: 
  validate , formalize , formalise