What is what does god speed mean?

Godspeed is an old English expression that is used to wish someone a safe and prosperous journey. The word "Godspeed" is derived from the Middle English phrase "God spede thee," which means "God prosper you." It is a way of saying good luck and may God be with you on your journey. The phrase is often used to wish someone well on a particularly long or dangerous journey. In modern times, the phrase is used more loosely to wish someone success in any endeavor or undertaking.