verb (v)

• declare invalid(verb.social)

  Synonym:
  annul, avoid, nullify, quash, void
  Antonym:
  formalise, formalize, validate
  

  source: wordnet30
• make invalid for use(verb.communication)

  Synonym:
  cancel
  

  source: wordnet30
• show to be invalid(verb.cognition)

  Synonym:
  nullify
  

  source: wordnet30
• take away the legal force of or render ineffective(verb.change)

  Example:
  Invalidate a contract.
  

  Synonym:
  vitiate, void
  Antonym:
  validate
  

  source: wordnet30
• To render invalid; to weaken or lessen the force of; to destroy the authority of; to render of no force or effect; to overthrow; as, to invalidate an agreement or argument.(verb)

  source: webster1913