- 落下，掉下，脱落：
The book dropped off his hand.
书从他手中掉下来。
His button has dropped off.
他的纽扣掉了。
- [口语]把…从车上卸下；(让…)下车，从(交通工具)上下来：
Drop me off at next stop.
请让我在下一个站下车。
- 把…放在，把…放下；把…交给某处：
to drop a letter off
寄出一封信
to drop the lanndry off
把要洗的东西交给洗衣店
Could you drop off the books at the library?
你能把这些书顺便还给图书馆吗?
- (数量)减少，变少；下降；衰落；萧条；衰弱：
Sales have dropped off.
销售量已下降了。
The membership of the club began to drop off.
这个俱乐部会员开始减少。
Flowers are dropping off.
花在凋谢。
- (质量)下降，变差：
The quality of work has dropped off since last month.
自上月起，工作质量已下降了。
- [口语]入睡，睡着；打瞌睡：
She was so tired that she dropped off in front of the television.
她很疲倦，在看电视时打盹。
He dropped off to sleep in the middle of the class.
在上课过程中他睡着了。
- (一个一个地)走掉，离开，一一散去；消失：
The attendance gradually dropped off.
与会者一一散去。
Her children have dropped off one by one.
她的孩子们一个一个地离开了她。
- [口语]死去：
The old woman dropped off in her sleep.
这老太婆在睡眠中死去了。