BREACH, in general, a breaking or an opening made by breaking; in law, the infringement of a right or the violation of an obligation or duty. The word is used in various phrases : breach of close, the unlawful entry upon another person's land (see TRESPASS) ; breach of covenant or contract, the non-fulfilment of an agreement to do or not to do some act (see DAMAGES) ; breach of the peace, disturbance of the public order (see also BREACH OF THE PEACE) ; pound-breach, taking by force out of a pound things lawfully impounded (see POUND) ; breach of prom ise of marriage, the non-fulfilment of a contract mutually entered into by a man and a woman that they will marry each other (see MARRIAGE) ; breach of trust, any deviation by a trustee from the duty imposed upon him by the instrument creating the trust (q.v.). In military science, a break or opening in the wall of a fortress, caused by bombardment by the artillery of the besieger or by his mines, and utilized by his storming parties in the assault. Also applied, loosely, to a penetration of an entrenched defensive position.