perjury, in criminal law, the act of willfully and knowingly stating a falsehood under oath or under affirmation in judicial or administrative proceedings. If the person accused of perjury had any probable cause for his belief that the statement he made was true, then he is not guilty of perjury. In U.S. federal law, and in most states, a false statement must be material to a point of inquiry in order to constitute perjury. Perjury is a crime and may be punished by fine or imprisonment. One can retract false testimony in the course of a criminal procedure without committing perjury. The crime of inducing another person to commit perjury is called subornation of perjury.

In law, act or crime of knowingly making a false statement while under oath. The statement must be material to the issue of inquiry. Perjuries that have the effect of obstructing the adjudication of a case may be given increased punishment for that reason. A person who makes a false statement and later corrects it is usually not considered to have committed perjury.

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