1 in, at or to the back of sb/sth （位置）在后面；向后面: There's a small garden behind the house. 房子后面有个小花园。The sun went behind a cloud. 太阳躲到云后面去了。You go on ahead. I'll follow on behind. 你继续往前走，我会跟在后面。Look behind you before you drive off. 开车离开之前要先看看后面。He ran off but the police were close behind. 他逃走了，但警察在后面紧追不舍。

2 behind (in/with) (sth) later or less good than sb/sth; making less progress than sb/sth 不及；落后于: The train is twenty minutes behind schedule. 火车误点二十分钟。Jane is behind the rest of the class in maths. 简的数学成绩落在其他同学后面。We are a month behind with the rent. 我们的房租晚交了一个月。 ☞Look at ahead. 参看 ahead。

3 supporting or agreeing with sb/sth 支持；赞成: Whatever she decides, her family will be behind her. 无论她作出什么决定，她的家人都会支持她。

4 responsible for causing or starting sth 造成；引起: What is the reason behind his sudden change of opinion? 他看法突然改变是什么原因？

5 used to say that sth is in sb's past （用于表示某事已成过去）: It's time you put your problems behind you(= forgot about them). 现在是你该忘记你这些问题的时候了。

6 in the place where sb/sth is or was. 在原处: Oh no! I've left the tickets behind(= at home). 哦，糟了！我把票忘在家里了。