used to wish someone good luck when they are setting out on a journey

祝成功;祝幸运;祝一路平安

这里的speed是其古意，表成功或繁荣。godspeed=May God speed (you)，特别是被祝福之人要开始一段旅行或开拓事业时。因成功之人多充实且忙碌，所以speed后来有了快速之意。

"Farewell and godspeed," the general said, ending his speech, and then it was time to go. "

“再见了，祝你一路顺风，”将军这样说道，结束了他的演讲，然后就是离开的时候了。