These words all mean to put an end to something. Void , abrogate and cancel are often used interchangeably with invalidate and with each other in specific contexts. To invalidate is to bring to an end the effectiveness of documents or claims. A faulty signature may invalidate a cheque. Evidence shown to be false may invalidate a claim in court. Negotiators may void a disputed clause in a contract, thereby invalidating its provisions. A government may abrogate a treaty, thus in effect invalidating it by declaring it no longer in force. A landlord may cancel a lease, thereby invalidating his tenant’s claim to shelter and his own claim to payment.

Abolish is applied to practices, condition s or social institutions.

• New Zealand abolished the death penalty for murder in 1941, restored it in 1950 and abolished it again in 1961; The Emancipation Proclamation abolished slavery in the United States; Sydney’s suburban trains became one-class in 1940, when the first- and second-class distinction was abolished .

To nullify is to prevent or end the effectiveness of some condition or activity. Often it means to counterpose an action or a condition that renders the original action or condition futile or inoperative: Counter-intelligence seeks to nullify the enemy’s espionage efforts. To negate , as here considered, is to prove an assertion false and thus render ineffective a claim based on it: The evidence of eye-witnesses negated the accused’s alibi. To annul is either to end something existing or to declare that it never really existed. An Act of Parliament may annul a charter and thus abolish its provisions. A court may annul a marriage, thus declaring that it never existed, rather than declaring a valid marriage at an end. To repeal and to rescind are to bring to an end the effect of a law or an order, respectively, and, by depriving them or the authority behind them, invalidate them. The British Government repealed the harsh Corn Laws in 1791. When issuing new regulations, a military headquarters may rescind earlier regulations governing the same subject.

To revoke is to bring to an end something that has been authoritatively given, permitted or granted.

• Evidence of forgery revoked the Donation of Constantine, which purported to establish that the Emperor Constantine the Great gave the Western roman Empire to the Papacy; King Louis XIV of France revoked the Edict of Nantes, in which King Henry IV had granted religious liberties to the French Huguenots; His licence was revoked for drunken driving.