“以牙还牙”，意思是用牙咬来对付牙咬，比喻用对方使用的手段来回击对方，以同样的方式报复，常与“以眼还眼”连用。可以翻译为“engage in a tit for tat”，英文习语“tit for tat”表示“a situation in which you do something to harm someone who has done something harmful to you”。
- 这种以牙还牙的报复还要持续多长时间？
How much longer is this tit for tat going to last? - 一个贩毒团伙的头目被对立的帮派枪杀了，于是这个团伙展开报复行动。这导致双方以牙还牙的交恶，从谋杀、绑架到纵火，整个城市因此陷入瘫痪状态。
A gang of drug dealers wanted to punish a rival gang for shooting their leader. That led to a tit for tat series of murders, kidnappings and arson that has paralyzed the city.
