1. 叛军；反叛者；叛乱者
    Rebels are people who are fighting against their own country's army in order to change the political system there.

    e.g. ...fighting between rebels and government forces.
           叛军和政府军之间的战争
    e.g. ...rebel forces in Liberia.
           利比里亚的叛军

2. （政党内部的）持不同政见者，反对派
    Politicians who oppose some of their own party's policies can be referred to as rebels.

rebel

    e.g. The rebels want another 1% cut in interest rates.
           反对派希望利率再降一个百分点。
    e.g. ...rebel MPs.
           持不同政见的国会议员

3. （政见不同者）反抗，反对
    If politicians rebel against one of their own party's policies, they show that they oppose it.

rebel的翻译

    e.g. More than forty Conservative MPs rebelled against the government and voted against the bill.
           40多个保守党议员反对政府的主张，对法案投了反对票。
    e.g. ...MPs planning to rebel over the proposed welfare cuts...
           打算反对削减社会福利提议的国会议员

4. 叛逆者;不循规蹈矩的人
    You can say that someone is a rebel if you think that they behave differently from other people and have rejected the values of society or of their parents.

    e.g. She had been a rebel at school.
           她在学校时就是个叛逆者。

5. 表现叛逆；不守规矩
    When someone rebels, they start to behave differently from other people and reject the values of society or of their parents.

    e.g. The child who rebels is unlikely to be overlooked...
           叛逆的孩子不太容易被忽视。
    e.g. I was very young and rebelling against everything.
           我当时非常年轻，对一切都表现出叛逆。