“Plead the fifth” is a colloquial phrase commonly used in the United States that refers to a person’s right to refuse to answer a question in a legal proceeding, in order to avoid incriminating themselves. The phrase comes from the Fifth Amendment of the United States Constitution, which states that no person shall be compelled in any criminal case to be a witness against themselves. Therefore, when someone “pleads the fifth,” they are choosing to remain silent rather than provide potentially incriminating information.