► illegalnot allowed by the law: Gambling is illegal in some states. They sent hundreds of illegal immigrants back to their countries.
► against the law against the law means the same as illegal but sounds slightly more informal: It is against the law to drive past a stopped school bus.
► unlawful formal illegal. Used especially when an action would be legal in a different situation: The arrests of hundreds of peaceful protesters were judged to be unlawful.
► unconstitutional not allowed by the constitution (=set of laws, rules, or principles) of a country or organization: The law was declared unconstitutional by the Supreme Court.
► criminal relating to crime or to committing crimes: The CEO and a vice president of the company were suspected of criminal activity.
► forbidden formal not allowed by rules or laws: Vehicles with more than two wheels are forbidden on the island.
► prohibited forbidden. Used especially on official signs and notices: Drinking alcohol on campus is strictly prohibited.
► banned forbidden. Used about things such as drugs and weapons that were legal but are now illegal: The runner was accused of using banned substances to improve his performance.
► illegitimate not allowed by rules or the law. Illegitimate is often used about governments or leaders that are not considered to have been elected in a legal way: The international community wants the illegitimate president to leave office.