辩护是指犯罪嫌疑人、被告人及其辩护人在刑事诉讼中，为保护自身的合法权益，针对控诉一方的指控而进行的证明其无罪、罪轻、减轻或免除罪责的反驳和辩解。

In civil proceedings and criminal prosecutions under the common law, a defendant may raise a defense (or defence) in an attempt to avoid criminal or civil liability. Besides contesting the accuracy of any allegation made against him or her in a criminal or civil proceeding, a defendant may also make allegations against the prosecutor or plaintiff or raise a defense, arguing that, even if the allegations against the defendant are true, the defendant is nevertheless not liable.