In practice. The arbitrament of the king or judge in punishing offeuses not directly censured by law. Jacob. So, “to be in mercy” signifies to be amerced or fined for bringing or defending an unjust suit, or to be liable to punishment in the discretion of the court. In criminal law. The discretion of a judge, within the limits prescribed by positive law, to remit altogether the punishment to which a convicted person is liable, or to mitigate the severity of his sentence; as when a jury recommends the prisoner to the mercy of the court,