What term describes an action that is not allowed under the Constitution?

The term "unconstitutional" specifically refers to actions, laws, or regulations that violate the principles or provisions outlined in the Constitution of a country. When something is deemed unconstitutional, it means that it goes against the foundational legal framework established by the Constitution, thus rendering it invalid within the legal system.

This term highlights the importance of the Constitution as the supreme law of the land. Courts and legal bodies have the authority to review and strike down any actions or legislation deemed unconstitutional. This mechanism is crucial for maintaining the rule of law and protecting the rights enshrined in the Constitution.

In contrast, while "illegal," "invalid," and "prohibited" may imply wrongdoing or a lack of legality, they do not specifically reference the breach of constitutional guidelines. "Unconstitutional" retains that unique context, focusing on the relationship between actions and constitutional standards.