1.tail用作名词是“尾巴”的意思,转化为动词作“跟踪,盯梢”解,指跟踪的人像尾巴一样紧紧地尾随着目标,观察其所作所为。这种跟踪可以表示较短暂的、较远距离的行动,含有动机不良的意味或暗示一种尾随而一直不被察觉的愿望。
2.tail有时也可作“给(某物体)装尾部〔巴〕”解。
3.tail可用作不及物动词,也可用作及物动词。用作不及物动词时,常与off连用; 用作及物动词时接名词或代词作宾语,可用于被动结构。

tail after(v.+prep.)
尾随,跟踪 follow close behind
▲tail after sb/sth
That dog is always seen tailing after its master.老是可以看见那条狗紧紧地跟在它主人后面。
An ambulance tailed after the marathon runners.一辆救护车跟在马拉松运动员的后面。

tail back(v.+adv.)
造成交通阻塞 form a traffic jam
▲tail back
The traffic was tailing back all the way to the city centre.道路交通一直阻塞到市中心。
Traffic tailed back for 15 miles when the road was blocked by an accident.当公路因事故受阻时,后面停下的车辆长达15英里。

tail off(v.+adv.)
▲tail off
1.零散地落在后面 fall behind or away in a scattered line
The second team tailed off behind.第二队零零落落地跟在后面。
2.变得越来越少〔小〕 go〔grow〕 progressively smaller in number, size, etc.
The attendants tailed off towards the end of the meeting.会议接近尾声时,人渐渐走光了。
The shower tailed off into a drizzle.阵雨越来越小,最后变成了毛毛雨。
The productivity in many foreign plants tailed off as the oil shortage sharpened last winter.去年冬天随着石油短缺加剧,许多外国工厂的生产率逐步下降。
3.变得越来越轻〔分散〕grow progressively fainter or more scattered
His voice tailed off as his courage failed.随着勇气的消失,他的声音也渐渐弱了。
His voice tailed off into silence.他的话音越来越低,终于哑然无声了。
The work of some students begins to tail off as they approach their examination.随着考试的临近,学生的课程量开始减少。
The report begins well but tails off in the final paragraphs.这篇报告开头写得不错,但到最后几段就逐渐逊色了。
Owing to little response, his speech tailed off to a hesitant end.由于得不到多少反应,他的演说吞吞吐吐地收了场。
His interest tailed oｆｆ toｗards the end oｆ the ｆilm.他的兴趣在电影临结束时荡然无存。

用作不及物动词
▲S+～(+A)
The ship tailed down stream.那船船尾朝下游停着。
用作及物动词
▲S+～+n./pron.
The police have been tailing me.警察一直在跟踪着我。
The deteｃtive tailed the thieｆ throｕｇh the ｃroｗd.侦探在人群中穿梭,尾随着小偷。
The secret agent tailed the spy to his hotel.该特工跟踪那个间谍到他住的旅馆。
He tailed the car until it had driven beyond the city boundary.他一直跟踪到那辆汽车驶出该城市的边界。
I tailed the model plane.我给模型飞机装了尾翼。
◇ 用于be ～ed结构
You are being tailed.有人在盯你的梢。

tail, chase, follow, pursue, tag, trail
参见follow条。

［同义词］ v.  chase, follow, pursue, tag, trail
［词源］  ＜古英语 ＜中古英语tægel(马尾巴)

1.tail用作名词的基本意思是“尾巴”“尾部”“后部”,常指动物的尾巴,也可指具体物的尾部,是可数名词。
2.tail用于比喻指人时可作“尾随的人”“暗探”解,指物时可作“尾巴似的东西,尾状物”解。
3.tail在口语中可作“燕尾服”解,此时通常用复数形式。
4.tail还可作“硬币的反面”解,与“head(正面)”相对,是可数名词。

make head or tail of
〈非正〉看懂 understand; find a meaning in
Can you make head or tail of his letter? 你能看懂他的信吗?
I have read the document through three times, but I can't make head or tail of it.我已把这文件从头至尾看了三遍,却仍然不解其意。
He used so many technical terms in his talk that the audience could not make head or tail of it.他在讲话中用了许多专门术语,听众简直摸不着头脑。

the tail wag the dog
尾巴摇狗; 〈喻〉本末倒置 situation in which a minor part of sth is controlling or determining the course of the whole
It is as though instead of a dog wagging its tail the tail should wag the dog.这情况恰似尾巴倒过来摇狗而不是狗摇尾巴了。
That the few right-wingers should exert such an influence on the policy of the party is a case of the tail wagging the dog.少数几个右翼分子对党的政策竟有这么大的影响,真是尾巴指挥狗——主次颠倒了。

turn tail
转身(逃走),逃跑 turn round defeated (and run away)
They fought for a few moments, then turned tail and fled.他们打斗了一会儿就转身逃跑了。
The fighters demolished an enemy tank and the other three turned tail and fled.士兵们干掉了敌人的一辆坦克,另三辆掉头逃窜了。

with one's tail between one's legs
夹着尾巴,垂头丧气,灰溜溜地 in a sad〔ashamed〕 manner
He came back with his tail between his legs.他垂头丧气地回来了。
He didn't seem at all sorry, but he went away with his tail between his legs after I made him apologize in front of everyone.他似乎没有丝毫歉意,但在我让他向大家道歉后,他垂头丧气地走掉了。

A fox cannot hide its tail.狐狸的尾巴是藏不住的。
You can touch a hibernating animal, or even pull its tail, without causing it to move or wake up.你可以摸冬眠的动物,甚至拉它的尾巴,也不会使它动一动或醒来。
The tiger lashed its tail about whenever anyone came near its cage.一有人走近笼子,老虎就不停地甩尾巴。
We knew the animal was in there, because it left its tail poking out.我们知道这动物在那里面,因为它的尾巴还露在外面。
The bird is colored yellowish on its back, wings and tail.这鸟的背部、翼、尾羽呈淡黄色。
This bird is easily recognized from its size and the unusual shape of its tail.通过体形的大小和形状特别的尾巴,可以容易地认出这是只什么鸟。
Some guinea pigs lack tails.有些豚鼠没有尾巴。
Coｗs ｕse their tails to keep aｗay ｆlies.牛常用尾巴驱赶苍蝇。
I prefer to sit towards the tail of the plane.我喜欢坐在靠尾部的机舱。
The tail won't come off the toy plane, it's fixed on with nails.玩具飞机的机尾掉不下来,它是用钉子钉住的。
We saw the tail of the procession disappearing round the bend.我们看着游行队伍的尾部消失在转弯处。
A ｃroｗd oｆ small boys ｆormed the tail oｆ the proｃession.一群小男孩走在队伍的尾部。
The poliｃe have put a tail on me so they knoｗ my every move.警方雇了一个暗探盯我的梢,所以我的一举一动他们都清楚。
For a ｆormal oｃｃasion at the palaｃe yoｕ mｕst ｗear tails.在宫廷正式的场合中,你应该穿燕尾服。
A coin has two sides, a head and a tail.硬币有正反两面。
Twice the coin came down tails.硬币两次落下时都是反面朝上。
Heads or tails?
Heads you do the dishes, tails I do them.你猜正面还是反面?正面你洗盘子,反面我来洗。