a.

1. 坏的，不好的；拙劣的；令人不悦的
   The weather was really bad.

   天气真糟。

2. 不健全的；有病的；疼痛的
   I felt bad all day.

   我整天觉得不舒服。

3. 有害的[（+for）]
   Reading in a dim light is bad for the eyes.

   在暗淡的光线下看书有损视力。

4. 严重的；厉害的
   She's got a bad headache.

   她头痛得厉害。

5. （食物）腐坏的；腐烂的
   The meat has gone bad.

   这肉已坏了。

6. 不适合的；不适当的
   They arrived at a bad time.

   他们来得不是时候。

7. 【口】遗憾的；后悔的[（+about/at）][+（that）]
   I feel bad about losing your dictionary.

   我很抱歉把你的字典丢失了。

8. 好极了的；棒极了的

n.

1. 不好的东西或情形[the S]
   You must learn to take the bad with the good.

   人必须学会好坏都能承受。

ad.

1. 【美】【口】坏
   Alison sings bad.

   艾丽森唱得很糟。

2. 【美】【口】很，非常

adj.

1. of poor quality or a low standard.
   ▸ (often bad at) not able to do a particular thing well.
   ▸inappropriate.
2. unwelcome or unpleasant.
   ▸severe or serious.
   ▸ (bad for) harmful to.
3. offending moral standards or accepted conventions.
4. injured, ill, or diseased.
5. (of food) decayed.
6. guilty; ashamed.
7. (badder, baddest)
   informal, chiefly N. Amer. good; excellent.