• (机器)出毛病,(病情)复发
• 表现不好; 行为不良; (机器)出毛病; 作弄; 开玩笑; (旧病)复发; 恶化

Verb:

1. misbehave badly; act in a silly or improper way;

   "The children acted up when they were not bored"
   

2. make itself felt as a recurring pain;

   "My arthritis is acting up again"
   

1.运作不正常；出毛病
If somethingis acting up, it is not working properly.

e.g. She was messing with the coffee pot, which was actingup again.
她正在鼓捣咖啡壶，那壶又坏了。

2.（孩子）耍脾气，捣蛋
If a childis acting up, they are behaving badly.

e.g. I could hear Jonathan actingup downstairs.
我能听见乔纳森在楼下撒泼。

1. 胡闹,出毛病：35. put one's foot in one's mouth - 祸从口出 | 41.actup - 胡闹,出毛病 | The children started toactup as soon as the teacher left the room. 老师一离开教室,孩子们就闹起来了.

2. 调皮：actup to 遵守 |actup 调皮 |actupon 遵照

3. 运作不正常：13.provided the transport comes though.若果交通顺利的话 |actup=运作不正常 | 14.Hit a sore spot,didnt I? 说到你痛处了,是不是?

4. 发作,尤指疾病发作：acquire a taste 对......有兴趣,开始喜欢 |actup 发作,尤指疾病发作 | addup 加,加起来,加到一起

If the pressure is too low, the heating system will act up.

如果压力太低, 供暖系统就会出毛病.

The children always act up when their mother is out.

母亲不在家,孩子们总是调皮捣蛋.

The young herdsman briskly mounted a horse that was inclined to act up with an unaccustomed rider.

年轻牧民轻快地跃上一匹惯于对生人使性子的马.

The question was so unexpected that , for a moment , she was at a loss how to act up properly.

问题来得这么突然, 她一时不知道如何作出恰当的反应.

Little children always act up with their parents at home.

小孩子们总在家里和父母耍脾气.

The car's engine began to act up.

汽车的发动机开始出毛病了.

I hat it when you act up.

你捣蛋的时候真令人讨厌.

Jack always used to act up when his mother wouldn't let him watch TV.

以前Jack的妈妈不让他看电视的时候,他就捣蛋.

We should act up to those principles and examples.

我们应遵循一些原则和实例.

We need to act up and stand for what we believe in.

我们需要做出反应,坚持我们所秉信的.

Watch Ricky, he sometimes likes to act up in class.

注意里基, 他总是喜欢在课堂上捣蛋.

Sometimes they act up and force you to take a stand.

有时他们行动起来并让你陪伴他们的左右.

Watch Ricky. He sometimes likes to act up in class.

注意里基,他有时喜欢在课堂上捣乱.

He like to act up and pretend that he is special.

他喜欢捣蛋胡闹,假装自己很特别.

The children always act up at home in holidays.

假期里,小孩经常在家顽皮.

• act up to遵守(履行)
• clean up one's act改变生活方式...
• act up出毛病
• act up to one's opinions照自己主意做事...