1. 定量;配给量
    When there is not enough of something, your ration of it is the amount that you are allowed to have.

    e.g. The meat ration was down to one pound per person per week...
           肉的配给量降到了每人每周一磅。
    e.g. They have begun to issue ration cards for basic necessities such as rice and flour.
           他们开始发行用来购买大米、面粉等生活基本必需品的定量配给卡。

2. （通常指由于紧缺）配给，定量供应
    When something is rationed by a person or government, you are only allowed to have a limited amount of it, usually because there is not enough of it.

    e.g. Staples such as bread, rice and tea are already being rationed...
           面包、大米和茶叶等日常必需品已实行配给。
    e.g. ...the decision to ration food...
           实行食物配给的决定

3. （给灾民或士兵的）给养，口粮
    Rations are the food which is given to people who do not have enough food or to soldiers.

    e.g. Aid officials said that the first emergency food rations of wheat and oil were handed out here last month...
           救助官员说第一批紧急援助的小麦和食用油是上月发放到这里的。
    e.g. The Russian soldiers sampled the officers' rations and wolfed the superior food with delight.
           俄军士兵尝了一下长官的配给食物，然后高高兴兴地把那些高级食物一扫而光。

4. 通常的量;定额
    Your ration of something is the amount of it that you normally have.

    e.g. ...after consuming his ration of junk food and two cigarettes.
           他像往常那样吃完垃圾食品、吸了两根烟后

5. see also: rationing