"Contempt of court" is when someone fails to obey an order of a court, disrespects the judge, disrupts the court proceedings through poor behavior, or publishes material deemed likely to jeopardize a fair trial
. It's often called simply "in contempt."
If a person is found guilty of contempt of court, a judge may impose a civil penalty (a fine) or criminal sanctions (jail time). Typically judges in common law systems have more extensive power to declare someone in contempt than judges in civil law systems.
Other forms of contempt are "Contempt of Congress" or "Contempt of Parliament." It's a separate offense from perjury, but a similiar one.