"head off" 是啥意思?All right,everyone,it's time to head off.

根据具体情境判断,如下：
head off
1.
拦截,上前拦住(使其转向或退回):
The running thief was headed off by the police.
那名夺路飞逃的小偷让警察给拦截住了.
2.
摆脱(跟踪者)；使改变话题:
From my house out,you have to head off several tails.
从我这儿出去,你得抛掉几个尾巴.
It's difficult to head her off when she talked about her dissolute life.
要是她谈起她的风流韵事来,你就别想岔开她的话题.
3.
防止；回避:
It's better for you to head off his coming.
你最好别让他来.
Talking with her,you'd try to head off your happy marrige.
和她交谈时你最好设法不去谈你的幸福的婚姻生活.
4.
赶在别人之前到达(某一重要地方):
It's important to head off the enemy from the airport.
抢在敌人之前占据飞机场是至关重要的.