1. 倒塌;塌下
    If a building or other structure collapses, it falls down very suddenly.

    e.g. A section of the Bay Bridge had collapsed...
           海湾大桥有一段垮塌了。
    e.g. The roof collapsed in a roar of rock and rubble...
           屋顶轰隆一声塌了下来，碎石瓦砾落了一地。

2. (体系或机构)崩溃，瓦解，突然失败
    If something, for example a system or institution, collapses, it fails or comes to an end completely and suddenly.

    e.g. His business empire collapsed under a massive burden of debt...
           他的商业帝国无力承担沉重的债务负担而垮掉了。
    e.g. This system has collapsed in most countries where it ruled...
           这一体系在其占统治地位的大多数国家都失败了。

3. (因生病或虚弱)突然倒下，昏倒
    If you collapse, you suddenly faint or fall down because you are very ill or weak.

    e.g. He collapsed following a vigorous exercise session at his home...
           在家剧烈运动了一阵后他突然昏倒了。
    e.g. It's commonplace to see people collapsing from hunger in the streets.
           在街上看见有人饿晕是很平常的事。

4. (因精疲力竭而)突然坐下(或倒下)
    If you collapse onto something, you sit or lie down suddenly because you are very tired.

    e.g. She arrived home exhausted and barely capable of showering before collapsing on her bed.
           她精疲力竭地回到家，勉强冲了个澡就倒在了床上。

5. 萎陷;内陷;瘪掉
    If something with air inside collapses, it falls inwards and becomes smaller or flatter.

    e.g. He plunged 300ft to the ground when his parachute collapsed...
           降落伞突然瘪了，他从300英尺的高空跌落到地面。
    e.g. He was rushed to hospital last week after suffering a collapsed lung.
           上星期，他因出现肺萎陷而被火速送进医院。