1. （婚姻、关系或联系的）破裂，终结
The break-up of a marriage, relationship, or association is the act of it finishing or coming to an end because the people involved decide that it is not working successfully.

e.g. Since the break-up of his marriage he had not formed any new relationships.
他婚姻破裂后没有谈新朋友。
e.g. ...the acrimonious break-up of the meeting's first session.
在争吵中结束的第一次会议

2. （组织或国家的）分裂，解体
The break-up of an organization or a country is the act of it separating or dividing into several parts.

e.g. ...the break-up of British Rail for privatisation...
在私有化过程中英国铁路公司的解体
e.g. At no time did a majority of Czechoslavakia's citizens support the country's break-up.
大多数捷克斯洛伐克公民一直反对国家分裂。