to invalidate or reverse a law, prohibition or a ruling etc The European Court of Justice has overturned a ban on tobacco advertising across Europe.
- The Court of Appeal overturned the decision of the High Court.
- The judgment was overturned on appeal.
- His conviction (=officially found guilty of a crime) was overturned after 5 years.
- The court overturned the ban on the new drug.
- Overturn is a broad term that can refer to either a single act or a process; for example a series of court decisions can have the effect of overturning another decision. Overrule is narrower and refers to what a higher court does when it abolishes a lower court's decision.