Main entry: vitiate, void, invalidate
Definition: take away the legal force of or render ineffective
Usage: invalidate a contract
Main entry: nullify, invalidate
Definition: show to be invalid
Main entry: invalidate, cancel
Definition: make invalid for use
Usage: cancel cheques or tickets
Main entry: void, avoid, annul, invalidate, nullify, quash
Definition: declare invalid
Usage: The contract was annulled; void a plea