出发英语高级表达怎么说

"Set off" is a common expression that means to start a journey or to depart from a place. You can also use "depart" or "leave" to express this idea. For example:

We set off for our vacation at 6:00 AM.
The train will depart from platform 3 at 10:00 AM.
We're leaving for the airport in an hour.

You could also use more formal or specific language, such as "commence a journey" or "embark on a trip."