ARD. In English law. A court instituted for the trial, during the recess of parliament, of peers indicted for treason or felony, or for misprision of either. This court is not a.permanent body, but is created in modern times, when occasion requires, and for the time being, only; and the lord high steward, so constituted, with such of the temporal lords as may take the proper oath, and act, constitute the court.