1. （关系的）破裂；（计划、讨论等的）失败，结束
    The breakdown of something such as a relationship, plan, or discussion is its failure or ending.

    e.g. ...the breakdown of talks between the US and EU officials.
           美国和欧盟官员间谈判的破裂
    e.g. ...the irretrievable breakdown of a marriage...
           无法挽回的婚姻破裂

2. 神经衰弱；精神崩溃
    If you have a breakdown, you become very depressed, so that you are unable to cope with your life.

    e.g. My personal life was terrible. My mother had died, and a couple of years later I had a breakdown...
           我个人的生活一团糟。母亲去世了，几年后我又患上了神经衰弱。
    e.g. They often seem depressed and close to emotional breakdown.
           他们经常显得很沮丧，精神濒于崩溃的边缘。

3. （汽车或机器的）故障，损坏
    If a car or a piece of machinery has a breakdown, it stops working.

    e.g. Her old car was unreliable, so the trip was plagued by breakdowns...
           她的旧车老不听使唤，一路上总是出故障。
    e.g. If you stop on the hard shoulder, wait for the police or breakdown service.
           如果你的车坏在路肩上了，就得等警察或修理站来帮忙。

4. 分类；细目列表
    A breakdown of something is a list of its separate parts.

    e.g. The organisers were given a breakdown of the costs.
           向组织者提供了一份开支细目。