go off有以下几层意思:
1、响起,例如:The alarm went off警铃骤然响起;
2、变质,例如This milk has gone off牛奶变坏了;
3、入睡,例如:Hasn't the baby gone off yet?婴孩还没入睡吗;
4、进行,例如:The plan went off well计划进行得很顺利。