Affirmative Defense，翻译为积极抗辩，其英文释义为Apart from denying a charge or claim, a defendant may assert affirmative defenses such as insanity, self-defense or entrapment to avoid criminal responsibility, or assert the statute of limitations or bankruptcy to avoid civil liability.

Affirmative Defense指被告并不否认原告所主张之事实的真实性，而是提出其他的理由来说明为什么自己不应承担责任的答辩。因此，它并不反驳原告诉求之真实性，而只是否认原告在法律上有起诉的权利。

一般说来,在美国刑法上，以下几种情况可以构成积极辩护的理由：

1.自我防卫（Self-defense）

2.挑衅和极端情绪波动

3.警察圈套

参考双语例句：

Furthermore, fair use is an affirmative defense, meaning that you would have to prove that your use was fair after you have been sued.

更近一步说，合理使用是一种积极抗辩，这意味着被起诉后，你需要证明你的使用是合理的。

Most affirmative defenses must be pleaded in a timely manner by a defendant in order for the court to consider them, or else they are considered waived by the defendant's failure to assert them.

大多数积极答辩必须由被告及时提出，以便法院考虑，否则若被告未能主张这些抗辩就被视为放弃。

It should be noted that liability insurance (or even a liability waiver) might not offer protection (or an affirmative defense) if a suit is filed.

应当指出，若诉讼被提交，则责任险(或甚至责任豁免)不提供保障(或积极抗辩)。