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.

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.