1、not worth a red cent

Worthless.

一文不值

e.g. I don't know how I'm going to tell that woman that her prized collectibles are not worth a red cent.

我不知道我要怎么告诉那位女士，她珍贵的收藏品其实一文不值。

a red cent

a cent is the smallest coin in value in American money and is worth very little.

在美国的货币里面值最小的硬币，几乎不值钱。

2、a red eye

an overnight airplane flight. a flight that leaves late at night and arrives early the next morning

夜间航班。深夜起飞，第二天清晨到达的航班。(American informal)

e.g. We took the red eye from Seattle to NewYork.

我们从西雅图乘深夜航班去纽约。

3、a red-letter day

a day that is very important or very special

非常重要或特别的一天

e.g. The day our daughter was born was a real red-letter day for us.

我们女儿出生的那一天对我们来说真的是非常特别的一天。

4、(boy,) is my face red!

An exclamation of acute embarrassment or mortification.

出于极度尴尬或屈辱的惊叫。（这里的“boy”也是感叹词啦(?￣??￣?? )！没有实际意义哦！）

e.g. I can't believe I was calling my client by the wrong name. Boy, is my face red!

我不敢相信我竟然叫错了客户的名字。真是太难堪了！

e.g. I spent so long on that report, only for it to be laughed at by everyone in class. Is my face red!

我在那篇报告上花了那么长的时间，也只是被班上每个人嘲笑。真是太丢脸了！

5、red as a cherry

bright red.

亮红；绯红

同样用法的还有：red as a poppy; red as a rose; red as a ruby; red as blood

e.g. When she came in from ice-skating, Clara's nose was as red as a cherry.

当Clara滑完冰回来，她的鼻子红彤彤的（像樱桃一样红）。

e.g. When her boss praised her in front of the whole office, Emily turned red as a poppy.

当Emily的老板在整个办公室前赞赏她，她脸一下子就红了。

6、red tape

official rules which do not seem necessary and make things happen very slowly

看起来不必要且导致拖延的官样规则和程序。“繁文缛节”

e.g. My passport application has been held up by red tape.

我的护照申请被繁文缛节搁置了。

e.g. Because of red tape, Frank took weeks to get a visa.

由于繁文缛节，Frank花了好几周才拿到签证。

e.g. Red tape prevented Jack's wife from joining him abroad.

繁文缛节导致Jack的妻子不能和他一起出国了。

7、see red

to be very angry.

非常生气。

e.g. Bill really saw red when the tax bill arrived.

当税单送到，Bill真的愤怒了。

e.g. Some Internet customers are seeing red as a result of the new virus that slowed Web traffic last week.

上周一种新的病毒减拖慢了网络流量，一些网络用户对这个结果十分生气。

e.g. When he laughed in my face, I just saw red.

他嘲笑我的脸时，我非常生气。

8、red sky at night, shepherd’s delight

A red sky at sunset is a sign that good weather will follow. The full phrase is "Red sky at night, shepherd's delight; red sky in the morning, shepherd's warning.”

日落时的红色天空，是下一天好天气的征兆。完整的说法是“傍晚天红，牧羊人高兴；早晨天红，牧羊人当心。”——这是一条关于天气的谚语，人们借助这些朗朗上口的谚语来判断明天的天气，其实也就是我们常说的“朝霞雨，晚霞晴” (??ω??)。

e.g. I think we're going to have a nice sunny day tomorrow. Look at that sunset—red sky at night, shepherd's delight.

我想明天将会是一个美好的晴天。你看那个日落——晚霞晴。

9、red ink

debt; indebtedness as shown in red ink>债务；债务在财务报表中用红色墨水表示。

e.g. There is too much red ink in my financial statement.

我的财务报表里太多赤字了。

e.g. Too much red ink and the company will collapse.

这个公司太多的赤字，就要倒闭了。

和它相对的是：out of the red

out of debt; into profitability.

摆脱债务；有盈利能力。

e.g. This year our company is likely to get out of the red before fall.

今年我们的公司在秋季之前可能就摆脱赤字了。

e.g. If we can cutdown on expenses, we can get out of the red fairly soon.

如果我们可以削减开销，我们很快就能拜托债务了。

10、paint the town red

to go out and enjoy yourself in the evening, often drinking a lot of alcohol and dancing

晚上出去玩得开心，经常是喝很多酒，还跳舞。(informal)

e.g. Jack finished his exams today so he's gone out to paint the town red.

今天Jack考完试了，所以他出去狂欢作乐了。

e.g. They were out painting the town red last night.

他们昨晚出去嗨了。

（来源：沪江英语）