a.

1. 偶然的，碰巧的
   My car had stalled and I sought help from casual passers-by.

   我的车发动不起来了，我就向碰巧路过的人求助。

2. 随便的，漫不经心的
   He tried to appear casual.

   他试图显得随便一点。

3. 不拘礼节的，非正式的
4. 临时的，不定期的[B]
   He worked as a casual laborer and did not earn much.

   他当临时工，没有赚多少钱。

n.

1. 临时工人[C]
2. 便装；便鞋[P]

adj.

1. relaxed and unconcerned.
   ▸made, done, or acting without much care or thought:

   a casual remark.
2. not regular or firmly established.
   ▸(of a worker) employed on a temporary or irregular basis.
   ▸(of a sexual relationship or encounter) occurring between people who are not established sexual partners.
3. happening by chance; accidental:
   a casual meeting.
4. without formality of style, manner, or procedure.

n.

1. Brit. a casual worker.
2. (casuals) clothes or shoes suitable for everyday wear rather than formal occasions.
3. Brit. a youth belonging to a subculture characterized by the wearing of expensive casual clothing.