crim. law. A security entered into before. Some competent court or officer, by a party accused, together with some other person, in the form of recognizance to the commonwealth in a certain sum of money, with, a condition that the accused shall keep the peace towards all the citizens of the commonwealth. A security for good behaviour is a similar recognizance with a condition that the accused shall be of good behaviour. 2. This security may be demanded by a court or officer having jurisdiction from all persons who threatened to kill or to, injure others, or who by their acts give reason to believe they will commit a breach of the peace. And even after an acquittal a prisoner may be required to give security of the peace or good behaviour, when the circumstances of the case justify a court in believing the public good requires it. 3. To obtain surety to keep the peace, the party requiring it must swear or affirm be fears a present or future danger, and not merely swear or affirm to a breach of the peace which is past; it is usual, however, to state such injuries, and when the circumstances warrant it, a threat of their repetition, as a legitimate ground for fearing future injury, which fear must always be stated.