后退：指向后移动，离开某个地方或远离某个对象。
放弃，退缩：指在面对困难、压力或威胁时，主动放弃或退缩。
back off // [ backing backed backs ]
动词词组 If you back off, you move away in order to avoid problems or a fight. 避开 (问题或争斗)
They backed off in horror.
他们吓得躲开了。
动词词组 If you back off from a claim, demand, or commitment that you made earlier, or if you back off it, you withdraw it. 撤回 (原来的主张、要求、承诺)
A spokesman says the president has backed off from his threat to boycott the conference.
一位发言人说，总统已经撤回了他抵制这次会谈的威胁。
退刀
... back off缓和，软化，减轻 all wet错误的 chow down吃饭 ...
... back down放弃（观点，意见，要求）；承认（错误）；认输 back off后退；不再逼迫（某人）做（考虑）某事 back up支持，证实 ...
Back off! There's no need to yell at me.
走开点！没必要对我大喊大叫。
The press have agreed to back off and leave the couple alone.
新闻界同意退让，不再搅扰这对夫妇。
If you're breathing too hard to talk in complete sentences, back off.
如果你呼吸太急促，甚至连话都说不全，就停下来吧。
A famous standoff took place there when boats arrived from each direction, and neither captain would back off.
VOA : standard.2010.04.29
He replied, once we verified there was no danger to a member's property, we had no choice but to back off according to our rules.
他回答道，根据公司规定，一旦确认会员财产无损，我们只能袖手旁观。
公正课程节选 : 耶鲁公开课
so we're one block off Golden Gate Park and ten blocks back off the ocean.
距金门公园一个街区，离海边有十个街区的路程。
SpeakingMax英语口语达人 : 溺爱女儿的父亲
Saturday,Palestinian President Mahmoud Abbas told Secretary Clinton the Palestinians will not back off their demand for Israel to freeze settlements before negotiations resume.
VOA : standard.2009.11.01
It shows bloody images of fisherman cutting the fins off dead sharks then throwing them back in the water.
VOA : special.2009.04.03
Even if he can't win in court, he'll persuade the Senate to back off.
The best coaches can motivate, know when to push and when to back off.
Starr has had to tell Smaltz to back off from delving into issues involving Clinton.
Back off（退避）：发生冲突时的强制性重传延迟。 大致意思就是网络上的节点在发送数据冲突后，等待一定时间后再发，等待时间是随指数增长 主要用于CSMA的冲突分解 用二进制指数退避可以取得较好的分解效果。 在共用信道的情况下，当冲突发生以后，每个节点都进行一个随机时延t,0<t<T t服从(0~T)上的以二为底的指数分布。