Perjury.

 Perjury refers to the act of deliberately providing false information or lying while under oath in a legal proceeding, such as during testimony in court or in a sworn affidavit. Perjury is considered a serious offense because it undermines the integrity of the justice system and can lead to miscarriages of justice.

The exact definition and penalties for perjury vary across jurisdictions, as laws may differ from country to country or even within different states or regions. However, perjury is generally considered a criminal offense punishable by law. The penalties for perjury can include fines, imprisonment, or a combination of both.

To prove perjury, the following elements are typically required to be established:

1. The person must make a false statement.
2. The false statement must be material to the proceeding in which it is made.
3. The person must have knowledge of the falsity of the statement.
4. The person must make the false statement willfully and with the intent to deceive.