1. 削弱;减弱
    If you weaken something or if it weakens, it becomes less strong or less powerful.

    e.g. The recession has weakened so many firms that many can no longer survive...
           经济衰退使许多公司实力大损，不少难以为继。
    e.g. The Prime Minister's opponents believe that her authority has been fatally weakened...
           首相的反对者认为她的权威已经受到致命削弱。

2. (使)(决心)动摇
    If your resolve weakens or if something weakens it, you become less determined or less certain about taking a particular course of action that you had previously decided to take.

    e.g. I looked at the list and felt my resolve weakening...
           我看着名单，觉得自己的决心正在动摇。
    e.g. Jennie weakened, and finally relented...
           詹妮的态度有所缓和，最终软了下来。

3. 使虚弱;使无力
    If something weakens you, it causes you to lose some of your physical strength.

    e.g. Malnutrition obviously weakens the patient.
           营养不良明显导致病人身体虚弱。

4. 使松动;使损坏
    If something weakens an object, it does something to it which causes it to become less firm and more likely to break.

weaken什么意思

    e.g. A bomb blast had weakened an area of brick on the back wall...
           一颗炸弹爆炸使后墙的一片砖发生了松动。
    e.g. Never dry underwear over direct heat; it will weaken the fabric.
           不要直接加热烘干内衣，那样会损坏布料。