a British Act of Parliament introduced on a temporary basis in 1984 to prevent terrorism (= the use of violence for political aims) in Northern Ireland. It gave the police power to arrest anyone suspected of terrorist activities and to hold them for 48 hours without giving a reason. It was replaced in 2000 by the Terrorism Act which had changes made to it by the Anti-terrorism, Crime and Security Act of 2001. In 2005 a new Prevention of Terrorism Act was passed which gave the Home Secretary the power to use ‘control orders’ to limit the freedom of people suspected of terrorism. This Act was later judged in a court to go against the individual's right to a fair trial under the European Convention on Human Rights, and it was repealed (= cancelled) in 2011.