- 掉下，掉落，掉出，落出：
One of her decayed teeth had dropped out.
她的一颗蛀牙掉了。
As he picked up the purse,the money dropped out.
他捡钱包时，钱掉了出来。
- 放弃；退出，不参与(某种活动)；(中途)退学：
She has dropped out of politics.
她已退出政界。
Teenagers who drop out of high school have trouble finding jobs.
中学辍学的青少年难找工作。
to drop out of school
中途退学
- (因不满世俗社会的道德标准和准则而)退出世俗(或习俗)社会，逃避现实，隐退：
They are dropping out and trying to find new ways of living.
他们在逃避社会现实并试图找到新的生活方式。
- (尤指词语等)过时，不再使用：
This word has virtually dropped out of usage today.
这个词实际上现在已不再使用了。
to be dropped out of use after a temporary vogue
时兴一阵之后便废弃不用
- 弃权，放弃(或退出)比赛：
He had injured his leg and had to drop out of the race.
他的腿伤了，不得不退出比赛。
- [俚语](数学题等)不证自明